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          USE flag index

          What are USE flags?
          For more information on the idea behind USE flags and how to use them, please see our documentation.

          Global USE flags

          Flag Description
          3dfx
          nginx
          X Add support for X11
          Xaw3d Add support for the 3d athena widget set
          a52 Enable support for decoding ATSC A/52 streams used in DVD
          aac Enable support for MPEG-4 AAC Audio
          aalib Add support for media-libs/aalib (ASCII-Graphics Library)
          accessibility Add support for accessibility (eg 'at-spi' library)
          acl Add support for Access Control Lists
          acpi Add support for Advanced Configuration and Power Interface
          adns Add support for asynchronous DNS resolution
          afs Add OpenAFS support (distributed file system)
          alsa Add support for media-libs/alsa-lib (Advanced Linux Sound Architecture)
          altivec Add support for optimizations for G4 and G5/ppc970 processors
          ao Use libao audio output library for sound playback
          apache2 Add Apache2 support
          aqua Include support for the Mac OS X Aqua (Carbon/Cocoa) GUI
          atm Enable Asynchronous Transfer Mode protocol support
          audiofile Add support for libaudiofile where applicable
          audit
          500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          Build in support for Ayatana notification using the libindicate or libappindicator plugin bash-completion Enable bash-completion support berkdb Add support for sys-libs/db (Berkeley DB for MySQL) bidi Enable bidirectional language support big-endian Big-endian toolchain support bindist Flag to enable or disable options for prebuilt (GRP) packages (eg. due to licensing issues) blas Add support for the virtual/blas numerical library bluetooth Enable Bluetooth Support branding Enable 沙巴体育 specific branding build !!internal use only!! DO NOT SET THIS FLAG YOURSELF!, used for creating build images and the first half of bootstrapping [make stage1] bzip2 Use the bzlib compression library cairo Enable support for the cairo graphics library calendar Add support for calendars (not using mcal!) canna Add support for the Canna kana to kanji conversion engine caps Use Linux capabilities library to control privilege cdb cdda Add Compact Disk Digital Audio (Standard Audio CD) support cddb Access cddb servers to retrieve and submit information about compact disks cdinstall Copy files from the CD rather than asking the user to copy them, mostly used with games cdr Add support for CD writer hardware cgi Add CGI script support cjk Add support for Multi-byte character languages (Chinese, Japanese, Korean) clamav Add support for Clam AntiVirus software (usually with a plugin) colord Support color management using x11-misc/colord connman Add support for net-misc/connman coreaudio Build the CoreAudio driver on Mac OS X systems cracklib Support for cracklib strong password checking crypt Add support for encryption -- using mcrypt or gpg where applicable css Enable reading of encrypted DVDs cups Add support for CUPS (Common Unix Printing System) curl Add support for client-side URL transfer library custom-cflags Build with user-specified CFLAGS (unsupported) cvs Enable CVS (Concurrent Versions System) integration cxx Build support for C++ (bindings, extra libraries, code generation, ...) dbi Enable dev-db/libdbi (database-independent abstraction layer) support dbm Add support for generic DBM databases dbus Enable dbus support for anything that needs it (gpsd, gnomemeeting, etc) debug Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see //wiki.gentoo.org/wiki/Project:Quality_Assurance/Backtraces dedicated Add support for dedicated game servers (some packages do not provide clients and servers at the same time) dga Add DGA (Direct Graphic Access) support for X djvu Support DjVu, a PDF-like document format esp. suited for scanned documents doc Add extra documentation (API, Javadoc, etc). It is recommended to enable per package instead of globally dri Enable direct rendering: used for accelerated 3D and some 2D, like DMA dts Enable DTS Coherent Acoustics decoder support dv Enable support for a codec used by many camcorders dvb Add support for DVB (Digital Video Broadcasting) dvd Add support for DVDs dvdr Add support for DVD writer hardware (e.g. in xcdroast) eds Enable support for Evolution-Data-Server (EDS) elogind Enable session tracking via sys-auth/elogind emacs Add support for GNU Emacs emboss Add support for the European Molecular Biology Open Software Suite encode Add support for encoding of audio or video files examples Install examples, usually source code exif Add support for reading EXIF headers from JPEG and TIFF images expat Enable the use of dev-libs/expat for XML parsing fam Enable FAM (File Alteration Monitor) support fastcgi Add support for the FastCGI interface fbcon Add framebuffer support for the console, via the kernel ffmpeg Enable ffmpeg/libav-based audio/video codec support fftw Use FFTW library for computing Fourier transforms filecaps Use Linux file capabilities to control privilege rather than set*id (this is orthogonal to USE=caps which uses capabilities at runtime e.g. libcap) firebird Add support for the Firebird relational database flac Add support for FLAC: Free Lossless Audio Codec fltk Add support for the Fast Light Toolkit gui interface fontconfig Support for configuring and customizing font access via media-libs/fontconfig fortran Add support for fortran freetds Add support for the TDS protocol to connect to MSSQL/Sybase databases freewnn 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          ftp Add FTP (File Transfer Protocol) support gd Add support for media-libs/gd (to generate graphics on the fly) gdbm Add support for sys-libs/gdbm (GNU database libraries) geoip Add geoip support for country and city lookup based on IPs geolocation Enable physical position determination ggi Add support for media-libs/libggi (non-X video api/drivers) gif Add GIF image support gimp Build a plugin for the GIMP git Enable git (version control system) support glut Build an OpenGL plugin using the GLUT library gmp Add support for dev-libs/gmp (GNU MP library) gnome Add GNOME support gnome-keyring Enable support for storing passwords via gnome-keyring gnuplot Enable support for gnuplot (data and function plotting) gnutls Prefer net-libs/gnutls as SSL/TLS provider (ineffective with USE=-ssl) gphoto2 Add digital camera support gpm Add support for sys-libs/gpm (Console-based mouse driver) gps Add support for Global Positioning System graphicsmagick Build and link against GraphicsMagick instead of ImageMagick (requires USE=imagemagick if optional) graphviz Add support for the Graphviz library gsl Use the GNU scientific library for calculations gsm Add support for the gsm lossy speech compression codec gstreamer Add support for media-libs/gstreamer (Streaming media) gtk Add support for x11-libs/gtk+ (The GIMP Toolkit) gtk-doc Build and install gtk-doc based developer documentation for dev-util/devhelp, IDE and offline use guile Add support for the guile Scheme interpreter gzip Compress files with Lempel-Ziv coding (LZ77) handbook Enable handbooks generation for packages by KDE hardened Activate default security enhancements for toolchain (gcc, glibc, binutils) hddtemp Enable monitoring of hdd temperature (app-admin/hddtemp) hdf5 Add support for the Hierarchical Data Format v5 headers-only Install only C headers instead of whole package. Mainly used by sys-devel/crossdev for toolchain bootstrap. hscolour Include coloured haskell sources to generated documentation (dev-haskell/hscolour) ibm Add support for IBM ppc64 specific systems iconv Enable support for the iconv character set conversion library icu Enable ICU (Internationalization Components for Unicode) support, using dev-libs/icu idn Enable support for Internationalized Domain Names ieee1394 Enable FireWire/iLink IEEE1394 support (dv, camera, ...) imagemagick Enable optional support for the ImageMagick or GraphicsMagick image converter imap Add support for IMAP (Internet Mail Application Protocol) imlib Add support for imlib, an image loading and rendering library infiniband Enable Infiniband RDMA transport support inotify Enable inotify filesystem monitoring support introspection Add support for GObject based introspection iodbc Add support for iODBC library ios Enable support for Apple's iDevice with iOS operating system (iPad, iPhone, iPod, etc) ipod Enable support for iPod device access ipv6 Add support for IP version 6 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          Add support for the JACK Audio Connection Kit java Add support for Java javascript Enable javascript support jbig Enable jbig-kit support for tiff, Hylafax, ImageMagick, etc jemalloc Use dev-libs/jemalloc for memory management jit Enable just-in-time compilation for improved performance. May prevent use of some PaX memory protection features in 沙巴体育 Hardened. joystick Add support for joysticks in all packages jpeg Add JPEG image support jpeg2k Support for JPEG 2000, a wavelet-based image compression format kde Add support for software made by KDE, a free software community kerberos Add kerberos support ladspa Enable the ability to support ladspa plugins lame 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          lapack Add support for the virtual/lapack numerical library lash Add LASH Audio Session Handler support latex Add support for LaTeX (typesetting package) lcms Add lcms support (color management engine) ldap Add LDAP support (Lightweight Directory Access Protocol) libass SRT/SSA/ASS (SubRip / SubStation Alpha) subtitle support libav Prefer libav over ffmpeg whenever both are supported libcaca Add support for colored ASCII-art graphics libedit Use the libedit library (replacement for readline) libffi Enable support for Foreign Function Interface library libnotify 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          libressl Use dev-libs/libressl instead of dev-libs/openssl when applicable (see also the ssl useflag) libsamplerate Build with support for converting sample rates using libsamplerate libwww Add libwww support (General purpose WEB API) lirc Add support for lirc (Linux's Infra-Red Remote Control) livecd !!internal use only!! DO NOT SET THIS FLAG YOURSELF!, used during livecd building lm-sensors Add linux lm-sensors (hardware sensors) support lua Enable Lua scripting support luajit Use dev-lang/luajit instead of dev-lang/lua (ineffective with USE=-lua) lzma Support for LZMA (de)compression algorithm lz4 Enable support for lz4 compression (as implemented in app-arch/lz4) lzo Enable support for lzo compression m17n-lib 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          mad Add support for mad (high-quality mp3 decoder library and cli frontend) magic Add support for file type detection via magic bytes (usually via libmagic from sys-apps/file) maildir Add support for maildir (~/.maildir) style mail spools matroska Add support for the matroska container format (extensions .mkv, .mka and .mks) mbox Add support for mbox (/var/spool/mail) style mail spools memcached Add support for memcached mhash Add support for the mhash library mikmod Add libmikmod support to allow playing of SoundTracker-style music files milter Add sendmail mail filter (milter) support minimal 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          mmap Add mmap (memory map) support mms Support for Microsoft Media Server (MMS) streams mng Add support for libmng (MNG images) modplug Add libmodplug support for playing SoundTracker-style music files modules Build the kernel modules mono Build Mono bindings to support dotnet type stuff motif Add support for the Motif toolkit mp3 Add support for reading mp3 files mp4 Support for MP4 container format mpeg Add libmpeg3 support to various packages mpi Add MPI (Message Passing Interface) layer to the apps that support it mplayer Enable mplayer support for playback or encoding mssql Add support for Microsoft SQL Server database mtp Enable support for Media Transfer Protocol multilib On 64bit systems, if you want to be able to compile 32bit and 64bit binaries musepack Enable support for the musepack audio codec musicbrainz Lookup audio metadata using MusicBrainz community service (musicbrainz.org) mysql Add mySQL Database support mysqli Add support for the improved mySQL libraries nas Add support for network audio sound ncurses Add ncurses support (console display library) neXt 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          neon Enable optimization support for ARM NEON processors netcdf Enable NetCDF data format support networkmanager Enable net-misc/networkmanager support nis Support for NIS/YP services nls 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          nntp Add support for newsgroups (Network News Transfer Protocol) nocd Install all files required to run the application without a CD mounted nsplugin Build plugin for browsers supporting the Netscape plugin architecture (that is almost any modern browser) ocaml Add support/bindings for the Ocaml language ocamlopt Enable ocamlopt support (ocaml native code compiler) -- Produces faster programs (Warning: you have to disable/enable it at a global scale) oci8 Add Oracle 8 Database Support oci8-instant-client Use dev-db/oracle-instantclient-basic as Oracle provider instead of requiring a full Oracle server install odbc Add ODBC Support (Open DataBase Connectivity) offensive Enable potentially offensive items in packages ofx 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          ogg Add support for the Ogg container format (commonly used by Vorbis, Theora and flac) openal Add support for the Open Audio Library openexr Support for the OpenEXR graphics file format opengl Add support for OpenGL (3D graphics) openmp Build support for the OpenMP (support parallel computing), requires >=sys-devel/gcc-4.2 built with USE="openmp" opus Enable Opus audio codec support oracle Enable Oracle Database support orc Use dev-lang/orc for just-in-time optimization of array operations osc Enable support for Open Sound Control oss 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          pam Add support for PAM (Pluggable Authentication Modules) - DANGEROUS to arbitrarily flip pch Enable precompiled header support for faster compilation at the expense of disk space and memory (>=sys-devel/gcc-3.4 only) pcmcia Add support for PCMCIA slots/devices found on laptop computers pcre Add support for Perl Compatible Regular Expressions pda Add support for portable devices pdf Add general support for PDF (Portable Document Format), this replaces the pdflib and cpdflib flags perl Add optional support/bindings for the Perl language php Include support for the PHP language pie Build programs as Position Independent Executables (a security hardening technique) plasma 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          plotutils Add support for plotutils (library for 2-D vector graphics) png Add support for libpng (PNG images) policykit Enable PolicyKit authentication support portaudio Add support for the crossplatform portaudio audio API posix Add support for POSIX-compatible functions postgres Add support for the postgresql database postscript Enable support for the PostScript language (often with ghostscript-gpl or libspectre) ppds Add support for automatically generated ppd (printing driver) files prefix Defines if a 沙巴体育 Prefix offset installation is used profile Add support for software performance analysis (will likely vary from ebuild to ebuild) pulseaudio Add support for PulseAudio sound server python Add optional support/bindings for the Python language qdbm Add support for the qdbm (Quick Database Manager) library qmail-spp Add support for qmail SMTP plugins qt5 Add support for the Qt 5 application and UI framework quicktime Add support for OpenQuickTime radius Add support for RADIUS authentication raw Add support for raw image formats rdp Enables RDP/Remote Desktop support readline Enable support for libreadline, a GNU line-editing library that almost everyone wants recode Enable support for the GNU recode library rss Enable support for RSS feeds ruby Add support/bindings for the Ruby language samba Add support for SAMBA (Windows File and Printer sharing) sasl Add support for the Simple Authentication and Security Layer savedconfig Use this to restore your config from /etc/portage/savedconfig ${CATEGORY}/${PN}. Make sure your USE flags allow for appropriate dependencies scanner Add support for scanner hardware (e.g. build the sane frontend in kdegraphics) sctp Support for Stream Control Transmission Protocol sdl Add support for Simple Direct Layer (media library) seccomp Enable seccomp (secure computing mode) to perform system call filtering at runtime to increase security of programs selinux !!internal use only!! Security Enhanced Linux support, this must be set by the selinux profile or breakage will occur semantic-desktop Cross-KDE support for semantic search and information retrieval session Add persistent session support skey Enable S/Key (Single use password) authentication support slang Add support for the slang text display library (it's like ncurses, but different) slp Add Service Locator Protocol support smartcard Enable smartcard support smp Enable support for multiprocessors or multicore systems snappy Enable support for Snappy compression (as implemented in app-arch/snappy) sndfile Add support for libsndfile snmp Add support for the Simple Network Management Protocol if available soap Add support for SOAP (Simple Object Access Protocol) sockets Add support for tcp/ip sockets socks5 Add support for the socks5 proxy sound Enable sound support source Zip the sources and install them sox Add support for Sound eXchange (SoX) speex Add support for the speex audio codec (used for speech) spell Add dictionary support split-usr Enable behavior to support maintaining /bin, /lib*, /sbin and /usr/sbin separately from /usr/bin and /usr/lib* sqlite Add support for sqlite - embedded sql database ssl Add support for SSL/TLS connections (Secure Socket Layer / Transport Layer Security) startup-notification Enable application startup event feedback mechanism static !!do not set this during bootstrap!! Causes binaries to be statically linked instead of dynamically static-libs Build static versions of dynamic libraries as well subversion Enable subversion (version control system) support suid Enable setuid root program, with potential security risks svg Add support for SVG (Scalable Vector Graphics) svga Add support for SVGAlib (graphics library) symlink Force kernel ebuilds to automatically update the /usr/src/linux symlink syslog Enable support for syslog systemd Enable use of systemd-specific libraries and features like socket activation or session tracking szip Use the szip compression library taglib Enable tagging support with taglib tcl Add support the Tcl language tcmalloc Use the dev-util/google-perftools libraries to replace the malloc() implementation with a possibly faster one tcpd Add support for TCP wrappers test Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently) theora Add support for the Theora Video Compression Codec threads Add threads support for various packages. Usually pthreads tidy Add support for HTML Tidy tiff Add support for the TIFF image format timidity Build with Timidity++ (MIDI sequencer) support tk Add support for Tk GUI toolkit truetype Add support for FreeType and/or FreeType2 fonts uclibc Enable uclibc specific patches and build or link uclibc udev Enable virtual/udev integration (device discovery, power and storage device support, etc) udisks Enable storage management support (automounting, volume monitoring, etc) unicode Add support for Unicode unwind Add support for call stack unwinding and function name resolution upnp Enable UPnP port mapping support upnp-av Enable UPnP audio/video streaming support upower Enable power management support usb Add USB support to applications that have optional USB support (e.g. cups) v4l Enable support for video4linux (using linux-headers or userspace libv4l libraries) vaapi Enable Video Acceleration API for hardware decoding vala Enable bindings for dev-lang/vala vanilla Do not add extra patches which change default behaviour; DO NOT USE THIS ON A GLOBAL SCALE as the severity of the meaning changes drastically vcd Video CD support vdpau Enable the Video Decode and Presentation API for Unix acceleration interface vhosts Add support for installing web-based applications into a virtual-hosting environment videos Install optional video files (used in some games) vim-syntax Pulls in related vim syntax scripts vnc Enable VNC (remote desktop viewer) support vorbis Add support for the OggVorbis audio codec wavpack Add support for wavpack audio compression tools wayland Enable dev-libs/wayland backend webkit Add support for the WebKit HTML rendering/layout engine webp Add support for the WebP image format wifi Enable wireless network functions wmf Add support for the Windows Metafile vector image format wxwidgets Add support for wxWidgets/wxGTK GUI toolkit x264 Enable h264 encoding using x264 xattr Add support for extended attributes (filesystem-stored metadata) xcb Support the X C-language Binding, a replacement for Xlib xcomposite Enable support for the Xorg composite extension xemacs Add support for XEmacs xface Add xface support used to allow a small image of xface format to be included in an email via the header 'X-Face' xft Build with support for XFT font renderer (x11-libs/libXft) xine Add support for the XINE movie libraries xinerama Add support for querying multi-monitor screen geometry through the Xinerama API xinetd Add support for the xinetd super-server xml Add support for XML files xmlrpc Support for xml-rpc library xmp Enable support for Extensible Metadata Platform (Adobe XMP) xmpp Enable support for Extensible Messaging and Presence Protocol (XMPP) formerly known as Jabber xosd Sends display using the X On Screen Display library xpm Add support for XPM graphics format xscreensaver Add support for XScreenSaver extension xv Add in optional support for the Xvideo extension (an X API for video playback) xvid Add support for xvid.org's open-source mpeg-4 codec zeroconf Support for DNS Service Discovery (DNS-SD) zip Enable support for ZIP archives zlib Add support for zlib (de)compression zsh-completion Enable zsh completion support zstd Enable support for ZSTD compression

          Local USE flags

          acct-user

          git

          gitea Set home directory for git hosting via www-apps/gitea.
          gitolite Set home directory for git hosting via dev-vcs/gitolite or dev-vcs/gitolite-gentoo.

          app-accessibility

          brltty

          api build brltty's application program interface
          beeper support the console tone generator
          contracted-braille support in-line contracted braille
          fm support for the sound card synthesizer
          louis Use braille tranlator dev-libs/liblouis
          midi support the musical instrument digital interface
          pcm support for sound card digital audio
          speech speech support

          eflite

          16k_voice Use a higher-quality voice.

          emacspeak

          espeak Adds support for the espeak tts engine

          freetts

          jsapi build Java Speech API (JSAPI)
          mbrola Adds support for mbrola voices

          orca

          braille Enable braille support

          simon

          opencv Use media-libs/opencv
          pim Enable support for KDE PIM resources integration
          sphinx Build sphinx backend (pulls app-accessibility/julius if disabled

          speech-dispatcher

          espeak Adds support for espeak speech engine
          flite Adds support for flite speech engine

          speechd-el

          brltty brltty support

          app-admin

          bcfg2

          cheetah Include dev-python/cheetah support
          genshi Include dev-python/genshi support
          server Installs scripts to be used on the server-side of this app

          calamares

          pythonqt Enable PythonQt-based module interface

          clsync

          cgroups Use cgroups to limit /dev access.
          cluster Enable clustering support (allows master-master clsync on multiple hosts). Not fully implemented yet.
          control-socket Enable AF_UNIX control socket support.
          extra-debug Enable extra debugging. This will hurt performance badly. Be ready for tons of output.
          extra-hardened Enable extra security checks. This will hurt performance.
          gio Enable GIO for FS monitoring (glib based alternative to inotify interface, not recommended; if both are compiled, may be selected at runtime).
          highload-locks Allows to use spinlocks for short delays instead of mutexes, but only on SMP systems.
          namespaces Enable namespaces isolation.

          conky

          apcupsd Enable support for sys-power/apcupsd
          bundled-toluapp Enable support for bundled toluapp. This only makes sense in combination with the lua-* flags
          cmus Enable monitoring of music played by media-sound/cmus
          eve Enable support for the eve-online skill monitor
          ical Enable support for events from iCalendar (RFC 5545) files using dev-libs/libical
          iostats Enable support for per-task I/O statistics
          irc Enable support for displaying everything from an irc channel using net-libs/libircclient
          lua-cairo Enable if you want Lua Cairo bindings
          lua-imlib Enable if you want Lua Imlib2 bindings
          lua-rsvg Enable if you want Lua RSVG bindings
          math Enable support for glibc's libm math library
          moc Enable monitoring of music played by media-sound/moc
          mpd Enable monitoring of music controlled by media-sound/mpd
          nano-syntax Enable syntax highlighting for app-editors/nano
          nvidia Enable reading of nvidia card temperature sensors via x11-drivers/nvidia-drivers
          portmon Enable support for tcp (ip4) port monitoring
          thinkpad Enable support for IBM/Lenovo notebooks
          weather-metar Enable support for metar weather service
          webserver Enable support to act as a webserver serving conkys output using net-libs/libmicrohttpd
          xmms2 Enable monitoring of music played by media-sound/xmms2

          conserver

          freeipmi Compile in FreeIPMI support via sys-libs/freeipmi

          diamond

          mongo Enable MongoDB support
          redis Enable Redis support

          diradm

          automount Support for automount data in LDAP
          irixpasswd Support for storing separate IRIX passwords

          elektra

          augeas Enable plugin for reading and writing configuration files with help from Augeas
          ini Enable new, advanced ini support
          simpleini Enable simpleini support
          uname Enable uname information for the key database
          yajl Enable yajl support

          gkrellm

          X Build both the X11 gui (gkrellm) and the server (gkrellmd). Disabling this flag builds the server only
          gnutls Enable SSL support for mail checking with net-libs/gnutls (overrides 'ssl' USE flag)
          hddtemp Enable monitoring harddrive temperatures via app-admin/hddtemp
          lm-sensors Enable monitoring sensors via sys-apps/lm-sensors
          ntlm Enable NTLM authentication for mail checking with net-libs/libntlm
          ssl Enable SSL support for mail checking with dev-libs/openssl

          glance

          swift Adds swift storage support

          gtkdiskfree

          gtk2 Support GTK+ 2.x instead of GTK+ 3.x

          hddtemp

          network-cron Monthly cronjob to update hddtemp.db.

          keepass

          aot Generate native code at build time, rather than runtime.

          keepassxc

          autotype Add support to autotype the passwords into other applications
          browser Enables browser plugin support
          keeshare Enable KeeShare sharing integration
          network Enable network support
          yubikey Enable database unlocking via YubiKey.

          lastpass-cli

          X Use x11-misc/xclip or x11-misc/xsel to copy passwords to the clipboard.
          pinentry Use app-crypt/pinentry to prompt for passwords.

          logrotate

          acl Installs acl support
          cron Installs cron file
          selinux Installs Security Enhanced Linux support

          logstash-bin

          x-pack Enable additional features (may need a license)

          matter

          entropy Add Entropy support

          mcollective

          client Install client utilities

          mms-agent

          monitoring Install the monitoring agent

          openrc-settingsd

          systemd Use the versions of dbus and polkit files provided by sys-apps/systemd

          packagekit-base

          command-not-found Enable packagekit support on shell "command not found"
          consolekit Use sys-auth/consolekit to get user session
          cron Install cron script for auto-update
          elogind Enable sys-auth/elogind support to get user session
          entropy Enable Entropy backend

          pass

          X Use x11-misc/xclip to copy passwords to the clipboard.
          dmenu Add support for x11-misc/dmenu with the 'passmenu' program.
          fish-completion Enable fish completion support.
          git Use dev-vcs/git for password revisions.
          importers Allow importing passwords from other password managers using various contributed scripts.

          pass-otp

          qrcode Add support for qrcodes using media-gfx/qrencode

          passwordsafe

          minimal Avoid collision with app-misc/pwsafe
          qr Enable QR code password display
          xml Enable XML import support
          xvkbd Install x11-misc/xvkbd on-screen keyboard
          yubikey Enable support for Yubikey

          prelude-manager

          dbx Enables Prelude Manager storing Prelude alerts into database through dev-libs/libpreludedb .
          tcpwrapper Enables Prelude Manager using tcp wrapper. It requires sys-apps/tcp-wrappers .

          puppet

          augeas Enable augeas support
          diff Enable diff support
          experimental Add patches for things in testing
          rrdtool Enable rrdtool support
          shadow Enable shadow support

          puppet-agent

          puppetdb Adds puppetdb support

          puppetserver

          puppetdb Adds support for connecting to puppetdb

          pwgen

          livecd Install init script for root password scrambling on boot

          pwman3

          mongodb Add support for MongoDB

          rsyslog

          clickhouse Build the ClickHouse output module (requires net-misc/curl)
          curl Enable http_request() function in RainerScript (requires net-misc/curl)
          dbi Build the general database output module (requires dev-db/libdbi)
          elasticsearch Build the Elasticsearch output module (requires net-misc/curl)
          gcrypt Add support for encrypted log files using dev-libs/libgcrypt
          gnutls Build the GnuTLS network stream driver (requires net-libs/gnutls)
          kafka Build the Apache Kafka input/output module (requires dev-libs/librdkafka)
          kerberos Build the GSSAPI input and output module (requires virtual/krb5)
          kubernetes Build the kubernetes modify plugin (requires net-misc/curl)
          libressl 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          mdblookup Build the MaxMind DB lookup message modify plugin using dev-libs/libmaxminddb
          mongodb Build the MongoDB output module (requires dev-libs/mongo-c-driver)
          mysql Build the MySQL database output module (requires virtual/mysql)
          normalize Build the normalize modify module (requires dev-libs/libee and dev-libs/liblognorm)
          omhttp Build the http output module (requires net-misc/curl)
          omhttpfs Build the httpfs output module (requires net-misc/curl)
          omudpspoof Build the udpspoof output module (requires net-libs/libnet)
          openssl Build the OpenSSL network stream driver (requires dev-libs/openssl)
          postgres Build the PostgreSQL database output module (requires dev-db/postgresql)
          rabbitmq Build the RabbitMQ output module (requires net-libs/rabbitmq-c)
          redis Build the Redis output module using (requires dev-libs/hiredis)
          relp Build the Reliable Event Logging Protocol (RELP) output module (requires dev-libs/librelp)
          rfc3195 Build the rfc3195 input module (requires dev-libs/liblogging)
          rfc5424hmac Build the rfc5424hmac modify module (requires dev-libs/openssl or dev-libs/libressl)
          snmp Build the snmp modify and output module (requires net-analyzer/net-snmp)
          ssl Add support for encrypted client/server communication (requires net-libs/gnutls)
          systemd Build the journal input and output module (requires sys-apps/systemd)
          usertools Installs the user tools (rsgtutil, rscryutil...) corresponding to the set USE flags
          uuid Include UUIDs in messages (requires sys-apps/util-linux)
          xxhash Enable xxHash support in fmhash module (requires dev-libs/xxhash)
          zeromq Build the ZeroMQ input and output modules (requires net-libs/czmq)

          sagan

          libdnet Add support for dev-libs/libdnet
          lognorm Add support for log/rules normalizations via dev-libs/liblognorm
          pcap Add support for network packet capture via net-libs/libpcap
          smtp Build witch SMTP (E-Mail) support
          snort Add support to interact with Snort IDE using net-analyzer/snortsam'

          sagan-rules

          lognorm Install normalize rules support with dev-libs/liblognorm

          salt

          cherrypy Enable support for using cherrypy.
          gnupg Enable support for gnupg via python-gnupg.
          keyring Enable support for keyrings via python-keyring.
          libcloud Enable salt-cloud support via libcloud.
          libvirt Support managing virtual machines with app-emulation/libvirt.
          mako Add support for using the mako template engine for parsing salt states.
          mongodb Support returning data to a mongodb server.
          neutron Support the OpenStack neutron network service.
          nova Enable support for the OpenStack Nova API
          openssl Add support for using TLS via OpenSSL.
          portage Add support for package state enforcement using sys-apps/portage
          raet Add support for the new RAET transport.
          redis Support returning data to a redis database.
          timelib Use timelib to parse english textual date descriptions.
          zeromq Add support for the zeromq transport.

          sudo

          gcrypt Use message digest functions from dev-libs/libgcrypt instead of sudo's
          libressl Use message digest functions from dev-libs/libressl instead of sudo's
          offensive Let sudo print insults when the user types the wrong password
          secure-path Replace PATH variable with compile time secure paths
          sendmail Allow sudo to send emails with sendmail
          sssd Add System Security Services Daemon support
          system-digest Use message digest functions from dev-libs/libgcrypt, dev-libs/libressl or dev-libs/openssl instead of sudo's internal SHA2 implementation

          sysklogd

          klogd Build and install (deprecated) kernel logging daemon
          logger Build the logger program
          logrotate use app-admin/logrotate for rotating logs rather than custom cron scripts

          syslog-ng

          amqp Enable support for AMQP destinations
          geoip2 Add support for geo lookup based on IPs via dev-libs/libmaxminddb
          http Enable support for HTTP destinations
          json Enable support for JSON template formatting via dev-libs/json-c
          kafka Enable support for Kafka destinations
          mongodb Enable support for mongodb destinations
          pacct Enable support for reading Process Accounting files (EXPERIMENTAL, Linux only)
          redis Enable support for Redis destinations
          smtp Enable support for SMTP destinations
          spoof-source Enable support for spoofed source addresses

          testdisk

          ewf Include ewf library
          ntfs Include the ability to read NTFS filesystems
          reiserfs Include reiserfs reading ability

          tripwire

          ssl Adds support for Secure Socket Layer connections
          static Builds the package statically
          tools Installs app-admin/mktwpol, providing scripts for the installation/setup of tripwire, including generating the tripwire policy file and maintenance of the tripwire database

          ulogd

          json Build JSON output plugin to save packets in JSON file format
          nfacct Build NFACCT input plugin to support traffic accounting via nfnetlink_acct
          nfct Build NFCT input plugin to support stateful flow-based logging via nfnetlink_conntrack
          nflog Build NFLOG input plugin to support stateless packet-based logging via nfnetlink_log
          pcap Build PCAP output plugin to save packets in libpcap file format
          ulog Build ULOG input plugin to support deprecated packet-based logging via ULOG target

          vault

          500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          Enable the Web UI

          webalizer

          xtended Include the 404 extension

          webapp-config

          portage Propagete python_targets dependencies to sys-apps/portage

          app-antivirus

          clamav

          clamdtop A Top like tool which shows what clamd is currently scanning amongst other things
          clamsubmit A tool to submit false positives / negatives
          libclamav-only Bypass building of libfreshclam and the ClamAV CLI applications.
          metadata-analysis-api Enables collection of file property metadata using ClamAV API for analysis by ClamAV bytecode programs.
          xml DMG and XAR support

          clamav-unofficial-sigs

          cron Install an hourly cron job to /etc/cron.d that runs the updates as the clamav user (instead of root), with an appropriate home directory and shell. The same cron job is installed as documentation when this flag is disabled.

          clamtk

          kde Install the Dolphin plugin.
          nautilus Install the Nautilus plugin.
          nemo Install the Nemo plugin.
          thunar Install the Thunar plugin.

          app-arch

          cabextract

          extras Install experimental extra tools: wince_info and wince_rename for examining and processing Windows CE installation cabinet header files; cabinfo for examining the structure of a cab file.

          cfv

          bittorrent Enable support for checking .torrent files

          deltarpm

          system-zlib Use system sys-libs/zlib. Do not enable features of rsync friendly.

          dpkg

          libmd Use app-crypt/libmd library for message digest functions
          update-alternatives Install update-alternatives

          dump

          ermt encrypted rmt support
          uuid Enable UUID support

          engrampa

          caja Enable engrampa to integrate with mate-base/caja by providing entries in its context menu
          packagekit Enable support for installing via app-admin/packagekit based on archive type

          file-roller

          nautilus Build contextual menu extension for gnome-base/nautilus.
          packagekit Enable support for the distro-neutral package manager GUI app-admin/packagekit

          gzip

          pic disable optimized assembly code that is not PIC friendly

          innoextract

          debug Enable debug logging and the --debug command-line option
          lzma Enable support for extracting lzma-compressed installers using app-arch/xz-utils

          libarchive

          blake2 Enable Blake2 hash support via app-crypt/libb2.
          bzip2 Allow accessing bzip2-compressed archives through libbz2 (which comes with app-arch/bzip2). This only affects libarchive's native support: bsdtar will keep using bunzip2 as a filter if that's not built-in.
          e2fsprogs Use file flags from sys-fs/e2fsprogs headers instead of virtual/os-headers headers
          nettle Use dev-libs/nettle as crypto backend
          zlib Allow accessing gzip-compressed archives through sys-libs/zlib. This only affects libarchive's native support: bsdtar will keep using gunzip as a filter if that's not built-in. It's also needed for supporting extraction of ZIP files.

          p7zip

          rar Enable support for non-free rar decoder

          pbzip2

          symlink Install symlinks which override app-arch/bzip2 implementation

          pigz

          symlink Install symlinks which override app-arch/gzip implementation

          rar

          all_sfx Install all SFX (Self-Extracting) files rather than just the native format (allows creation of Windows EXEs on Linux ELF systems)

          tar

          minimal just install `tar`

          unzip

          natspec Use dev-libs/libnatspec to correctly decode non-ascii file names archived in Windows.

          wimlib

          fuse Use fuse libraries
          iso Install app-cdr/cdrtools in order to prepare iso images
          ntfs Use libntfs-3g library from sys-fs/ntfs3g
          openssl Use the SHA-1 message digest from libcrypto instead of compilling another implementation
          yasm Use yasm assembler instead of nasm

          xz-utils

          extra-filters Build additional filters that are not used in any of the default xz presets. This includes delta and BCJ coders, additional match finders and SHA256 checks.

          zip

          natspec Use dev-libs/libnatspec to correctly decode non-ascii file names archived in Windows.

          app-backup

          amanda

          ndmp Support for the NDMP protocol
          s3 Support for backing up to the Amazon S3 system
          xfs Support for backing up raw XFS filesystems using xfsdump

          backup-manager

          s3 Support for backing up to the Amazon S3 system

          bacula

          bacula-clientonly Disable DB support, and just build a client
          bacula-nodir Disable building of director
          bacula-nosd Disable building of storage daemon
          batch-insert Enable batch insert into data base
          logwatch Install support files for logwatch

          bareos

          cephfs Enable cephfs storage backend
          clientonly Only install file-daemon (client)
          director Install director
          fastlz Enable support vor lz4, lz4hc and lzfast using dev-libs/bareos-fastlzlib
          glusterfs Enable glusterfs storage backend
          gnutls When ssl is enabled, use GnuTLS instead of OpenSSL
          jansson JSON API support using JANSSON for director
          lmdb enable build of LMDB support for faster accurate backup
          logwatch Install support files for logwatch
          ndmp Enable support for NDMP (Network Data Management Protocol)
          rados Enable rados storage backend
          rados-striper Enable use of rados-striper
          scsi-crypto Enable low level SCSI crypto support
          sql-pooling Enable SQL pooling support
          storage-daemon Install storage daemon (bareos-sd)

          btrbk

          mbuffer Use sys-block/mbuffer to enable progress bar and buffering/limiting functionality
          pv Use sys-apps/pv to enable progress bar functionality

          bup

          web Support browsing backups via a web interface

          dar

          dar32 Enables --enable-mode=32 option, which replace infinite by 32 bit integers
          dar64 Enables --enable-mode=64 option, which replace infinite by 64 bit integers
          gcrypt Enables strong encryption support
          gpg 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          deja-dup

          nautilus Build gnome-base/nautilus extension

          duplicity

          s3 Support for backing up to the Amazon S3 system

          rear

          udev Have ReaR start backup when attaching your USB drive.

          snapper

          lvm Enable LVM thinprovisioned snapshots support sys-fs/lvm2
          xattr Add support for getting and setting POSIX extended attributes, through sys-apps/attr.

          tsm

          tsm_cit IBM Tivoli Common Inventory Technology
          tsm_hw Difference snapshot support for NetApp and N-Series file servers

          zbackup

          tartool Install tartool utility

          app-benchmarks

          filebench

          auto-completion Enable command-line autocompletion using dev-libs/libtecla

          httperf

          idleconn Build with the idleconn program

          ioping

          netdata Add support for netdata

          ramspeed

          pic Force shared libraries to be built as PIC (this is slower)

          sysbench

          aio Enable libaio support

          app-cdr

          brasero

          libburn Enable dev-libs/libburn backend
          nautilus Build the gnome-base/nautilus extension
          packagekit Enable support for the distro-neutral package manager GUI app-admin/packagekit
          playlist Enable support for playlists through dev-libs/totem-pl-parser
          tracker Enable audio playlist search using the app-misc/tracker indexer

          cdemu

          cdemu-daemon Pull app-cdr/cdemu-daemon dependency, useful in chroot environment (bug #315491). Do not disable until you know what you are doing.

          dvdisaster

          debug Enable memory debugging.

          gaffitter

          scripts Install additional gaffitter scripts for external programs

          mirage2iso

          pinentry Support app-crypt/pinentry password input backend.

          app-crypt

          aespipe

          asm Enable assembly modules
          cpu_flags_x86_padlock Use VIA padlock instructions, detected at run time, code still works on non-padlock processors

          ccid

          kobil-midentity Build and install Kobil_mIDentity_switch tool
          twinserial Enable twinserial reader

          codecrypt

          cryptopp Build algorithms that need Crypto++ support dev-libs/crypto++

          dehydrated

          cron Install cron job to sign/renew non-existent/changed/expiring certificates

          eid-mw

          dialogs Enable "askaccess" dialog box, by using x11-libs/gtk+
          gtk All dialogs are available, by using x11-libs/gtk+
          p11-kit Support for app-crypt/p11-kit.
          p11v220 Enable PKCS#11 v2.20 features.

          ekeyd

          minimal Only install the ekey-egd-linux service rather than the full ekeyd package.
          munin Install a plugin for net-analyzer/munin to graph statistical data from ekeyd.
          usb Build the libusb-based userland daemon for accessing the EntropyKey (alternative to the CDC USB driver). It is suggested to use this option by default, as the CDC driver in the kernel often seems to be fragile (or the gadget implementation on the EntropyKey is too buggy), and can cause various problems.

          gnupg

          smartcard Build scdaemon software. Enables usage of OpenPGP cards. For other type of smartcards, try app-crypt/gnupg-pkcs11-scd. Bring in dev-libs/libusb as a dependency; enable scdaemon.
          tofu Enable support for Trust on First use trust model; requires dev-db/sqlite.
          tools Install extra tools (including gpgsplit and gpg-zip).
          usb Build direct CCID access for scdaemon; requires dev-libs/libusb.
          user-socket try a socket directory which is not removed by init manager at session end
          wks-server Install the wks-server

          gnupg-pkcs11-scd

          proxy Build the gnupg-pkcs11-scd-prox

          gpgme

          common-lisp Install common-lisp files

          hashcat

          brain Enable the hashcat brain

          heimdal

          hdb-ldap Adds support for LDAP as a database backend
          lmdb Add support for using dev-db/lmdb for lookup tables
          otp Adds support for one-time passwords
          pkinit Adds support for PKINIT for the initial ticket

          hmaccalc

          fips Enable NSS FIPS mode and support only the FIPS-compliant functions

          johntheripper-jumbo

          opencl Build with opencl/GPU cracking support
          pcap Build with pcap support

          kbfs

          git Build the Git remote helper for storing repositories in Keybase

          kstart

          afs Enables afs support which means you can acquire an afs token and set PAGs. It's recommended to set this USE if you need authenticated access to an AFS cell for your daemon/app.

          libb2

          native-cflags Use CFLAGS as determined by configure script. These flags will enable all CPU specific features it find available, to further optimise the implementation. This discards any existing CFLAGS set in make.conf or similar.

          libu2f-host

          systemd 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          mit-krb5

          doc Creates and installs the API and implementation documentation. This is only useful if you want to develop software which depends on kerberos
          keyutils Enable for the keyring ccache using keyutils
          lmdb Add support for using dev-db/lmdb for lookup tables
          openldap Enable support for ldap as a database backend
          pkinit Enable pkinit support for the initial ticket

          ophcrack

          tables Require the additional tables used to carry out cracking (app-crypt/ophcrack-tables)

          ophcrack-tables

          vistafree Installs the free Vista ophcrack tables
          xpfast Installs the fast XP ophcrack tables
          xpsmall Installs the small free XP ophcrack tables

          p11-kit

          asn1 Enable ASN.1 certificate support
          trust Build the trust policy module

          qca

          botan Enable botan plugin
          gcrypt Enable gcrypt plugin
          gpg Enable GnuPG plugin
          logger Enable logger plugin
          nss Enable NSS plugin
          pkcs11 Enable PKCS#11 plugin
          sasl Enable SASL plugin
          softstore Enable softstore plugin

          seahorse

          ldap Enable seahorse to manipulate GPG keys on a LDAP server.

          swtpm

          fuse Support sys-fs/fuse based /dev/tpm interface

          tpm-emulator

          mtm-emulator Build the MTM emulator

          tpm-tools

          pkcs11 Build Token data management utilities based on OpenCryptoki's (dev-libs/opencryptoki) PKCS#11 implementation.

          tpm2-tss

          gcrypt Use dev-libs/libgcrypt as crypto engine
          openssl Use dev-libs/openssl as crypto engine

          veracrypt

          asm Enable assembly for optimization

          zulucrypt

          gnome Enable support for the freedesktop.org Secret Service API via app-crypt/libsecret
          kwallet Enable encrypted storage of passwords with kde-frameworks/kwallet
          udev Whether udev will be consulted when deciding if a volume is system or not

          app-dicts

          aspell-be

          classic Support classic spelling by default

          gwaei

          hunspell Enable app-text/hunspell spellchecking and morphological analysis
          mecab Enable app-text/mecab support

          myspell-pt

          preao Use the pre ortographic agreement version of the dictionary

          app-doc

          clsync-docs

          api Install doxygen generated API docs.

          csound-manual

          html Install HTML documentation

          devmanual

          fallback Use alternative minimal stylesheet instead of tyrian theme.

          doxygen

          clang support for sys-devel/clang assisted parsing
          dot allow to create dot graphs using media-gfx/graphviz
          doxysearch build doxyindexer and doxysearch.cgi

          kicad-doc

          html Generate documentation in HTML format
          pdf Generate documentation in PDF format

          linuxfromscratch

          htmlsingle Install all-on-one-page HTML version.

          pms

          html Generate and install PMS as .html as well
          twoside Enable two-sided layout suitable for printing

          pms-bin

          html Install PMS as .html as well

          tldp-howto

          html Install multi-chapter HTML docs
          htmlsingle Install all-on-one-page HTML docs
          pdf Install pdf docs
          text Install plain-text docs

          app-editors

          bluefish

          gtk3 Enable GTK3 interface (default)
          gucharmap Enable gucharmap dictionary plugin
          python Enable Python integration for zen-coding plugin
          spell Enable spell checking capabilities via enchant library

          emacs

          athena 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          dynamic-loading Enable loading of dynamic libraries at runtime
          games Support shared score files for games
          gconf Use gnome-base/gconf to read the system font name
          gfile Use gfile (dev-libs/glib) for file notification
          gsettings Use gsettings (dev-libs/glib) to read the system font name
          gtk2 Prefer version 2 of the GIMP Toolkit to version 3 (x11-libs/gtk+)
          gzip-el Compress bundled Emacs Lisp source
          imagemagick Use media-gfx/imagemagick for image processing
          libxml2 Use dev-libs/libxml2 to parse XML instead of the internal Lisp implementations
          mailutils Retrieve e-mail using net-mail/mailutils instead of the internal movemail substitute
          source Install C source files and make them available for find-function
          toolkit-scroll-bars Use the selected toolkit's scrollbars in preference to Emacs' own scrollbars
          wide-int Prefer wide Emacs integers (typically 62-bit). This option has an effect only on architectures where "long" and "long long" types have different size.
          xwidgets Enable use of GTK widgets in Emacs buffers (requires GTK3)

          emacs-vcs

          athena 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          dynamic-loading Enable loading of dynamic libraries at runtime
          games Support shared score files for games
          gconf Use gnome-base/gconf to read the system font name
          gfile Use gfile (dev-libs/glib) for file notification
          gsettings Use gsettings (dev-libs/glib) to read the system font name
          gtk2 Prefer version 2 of the GIMP Toolkit to version 3 (x11-libs/gtk+)
          gzip-el Compress bundled Emacs Lisp source
          harfbuzz Use media-libs/harfbuzz as text shaping engine
          imagemagick Use media-gfx/imagemagick for image processing
          json Compile with native JSON support using dev-libs/jansson
          libxml2 Use dev-libs/libxml2 to parse XML instead of the internal Lisp implementations
          mailutils Retrieve e-mail using net-mail/mailutils instead of the internal movemail substitute
          source Install C source files and make them available for find-function
          threads Add elisp threading support
          toolkit-scroll-bars Use the selected toolkit's scrollbars in preference to Emacs' own scrollbars
          wide-int Prefer wide Emacs integers (typically 62-bit). This option has an effect only on architectures where "long" and "long long" types have different size.
          xwidgets Enable use of GTK widgets in Emacs buffers (requires GTK3)

          fe

          sendmail Send mail after editor abend

          gedit-plugins

          charmap Insert special characters just by clicking on them
          git Shows document changes related to git's HEAD
          terminal Embed a terminal in the bottom pane

          gnome-latex

          latexmk Install dev-tex/latexmk (used by default for the build tools)
          rubber Install dev-tex/rubber (can be used for the build tools)

          gvim

          cscope Enable cscope interface
          gtk2 Enable GTK+2 interface
          netbeans Include netbeans external editor integration support
          racket Enable support for Scheme using dev-scheme/racket

          jasspa-microemacs

          nanoemacs Build NanoEmacs instead of MicroEmacs

          joe

          xterm Enable full xterm clipboard support

          leafpad

          emacs Enable Emacs key theme

          mousepad

          gtk3 Use GTK+3 instead of GTK+2

          nano

          debug Enable debug messages and assert warnings. Note that these will all be sent straight to stderr rather than some logging facility.
          justify Enable justify/unjustify functions for text formatting.
          magic Add magic file support (sys-apps/file) to automatically detect appropriate syntax highlighting
          minimal Disable all fancy features, including ones that otherwise have a dedicated USE flag (such as spelling).
          split-usr Enable this if /bin and /usr/bin are separate directories

          ne

          tinfo Link against libtinfo from sys-libs/ncurses

          neovim

          clipboard Enable clipboard support through a provider
          nvimpager Install nvimpager symlink to less.sh macro
          remote Enable support for remote options using nvr
          tui Build the neovim unix tui

          okteta

          designer Build plugins for dev-qt/designer

          qhexedit2

          gui Install Qt5 hex editor

          tea

          aspell Enable spellchecking using app-text/aspell
          hunspell Enable spellchecking using app-text/hunspell
          qml Enable support for plugins using QML

          vim

          X Link console vim against X11 libraries to enable title and clipboard features in xterm
          cscope Enable cscope interface
          racket Enable support for Scheme using dev-scheme/racket
          terminal Enable terminal emulation support
          vim-pager Install vimpager and vimmanpager links

          vis

          tre more memory efficient regex search using dev-libs/tre

          xemacs

          athena Chooses the MIT Athena widget set
          dnd Enables support for the x11-libs/dnd drag-n-drop library
          eolconv Support detection and translation of newline conventions
          mule Add multi-language support to XEmacs
          pop Support POP for mail retrieval
          xim Enable X11 XiM input method

          zile

          valgrind Enable usage of dev-util/valgrind in tests

          app-emacs

          auctex

          preview-latex Use bundled preview-latex

          bbdb

          tex Install plain TeX support files
          vm Add support for app-emacs/vm

          calfw

          howm Add support for the app-emacs/howm note-taking tool

          elscreen

          wanderlust Include support for app-emacs/wanderlust

          emacs-common-gentoo

          games Support shared score files for games

          emacs-w3m

          gzip-el Compress bundled Emacs Lisp source

          mu-cite

          bbdb Include support for app-emacs/bbdb

          org-mode

          contrib Install user-contributed files
          odt-schema Install non-free schema files for OpenDocument Text exporter

          remember

          bbdb Include support for app-emacs/bbdb
          planner Include support for app-emacs/planner

          slime

          xref Install xref.lisp cross-referencing tool

          vm

          bbdb Include support for app-emacs/bbdb

          wanderlust

          bbdb Include support for app-emacs/bbdb

          wikipedia-mode

          outline-magic Enable support for outline-mode extensions (app-emacs/outline-magic)

          app-emulation

          aranym

          clipboard Enable bidirectional clipboard transfer between the host and FreeMiNT
          jit Build Just-In-Time compiler variant with increased performance
          lilo Enable support for directly booting kernels such as Linux
          osmesa Allow images to be rendered in memory using the host CPU
          pmmu Build full PMMU variant, required for running mainline Linux
          standard Build standard (no JIT or PMMU) variant

          bochs

          3dnow Enable support for emulating 3DNow! instructions (incomplete)
          avx Enable support for emulating Advanced Vector Extensions (AVX)
          debugger Enable debugger (slows down emulation)
          gdb Enable support for the remote GDB stub
          x86-64 Enable support for emulation of 64-bit CPUs

          containerd

          apparmor Support for AppArmor
          btrfs Support for BTRFS snapshot driver
          cri Support for Kubernetes CRI

          containers-storage

          btrfs Enables dependencies for the "btrfs" graph driver, including necessary kernel flags.
          device-mapper Enables dependencies for the "devicemapper" graph driver, including necessary kernel flags.

          cri-o

          btrfs Enables dependencies for the "btrfs" graph driver, including necessary kernel flags.
          device-mapper Enables dependencies for the "devicemapper" graph driver, including necessary kernel flags.
          ostree Enables dependencies for handling of OSTree images.

          crossover-bin

          capi Enable ISDN support via CAPI
          opencl Enable OpenCL support

          crun

          bpf Enable in Kernel, eBPF (enhanced Berkley Packet Filter) support for managing device controllers.

          docker

          apparmor Enable AppArmor support.
          aufs Enables dependencies for the "aufs" graph driver, including necessary kernel flags.
          btrfs Enables dependencies for the "btrfs" graph driver, including necessary kernel flags.
          container-init Makes the a staticly-linked init system tini available inside a container.
          device-mapper Enables dependencies for the "devicemapper" graph driver, including necessary kernel flags.
          overlay Enables dependencies for the "overlay" graph driver, including necessary kernel flags.

          docker-credential-helpers

          gnome-keyring Build secretservice helper which works with gnome-keyring or kwallet using D-Bus.
          pass Build pass helper for the pass utility.

          docker-runc

          ambient Enable support for ambient capability
          apparmor Enable AppArmor support

          dosemu

          fluidsynth use media-sound/fluidsynth for MIDI emulation

          faudio

          ffmpeg FAudio has optional support for decoding xWMA resources using FFmpeg, requiring: media-video/ffmpeg (note: this feature is not supported by media-video/libav).
          test Build and run faudio testsuite.
          utils Build all faudio utilities.
          xnasong Build support for optional XNG_SONG component (note: this not required by app-emulation/wine-staging, app-emulation/wine-vanilla for faudio XAudio support).

          fs-uae

          fmv Enable support for CD32 FMV (full motion video)
          glew Enable support for The OpenGL Extension Wrangler Library (media-libs/glew)

          fs-uae-launcher

          lha Enable LHA archive support

          fuse

          backend-X Use X11 rendering backend
          backend-fbcon Use framebuffer rendering backend
          backend-sdl Use SDL rendering backend
          backend-svga Use svgalib rendering backend
          memlimit Add compile-time memory usage limiting

          fuse-utils

          gcrypt Use dev-libs/libgcrypt for low-level crypto of some features, including logfiles.

          ganeti

          drbd Enable DRBD support
          experimental Enable experimental patches. Warning! This will break RPC within major versions if the patches applied differ!
          haskell-daemons Build haskell daemons instead of python
          htools Enable htools support
          kvm Enable KVM support
          lxc Enable Linux Countainers support
          monitoring Enable the ganeti monitoring daemon
          multiple-users Enable support for running VMs as different users
          rbd Enable rados block device support via sys-cluster/ceph
          restricted-commands Enable restricted commands in the node daemon
          xen Enable Xen support

          hyperd

          libvirt Enable support for KVM via libvirt
          xen Enable support for the Xen Hypervisor

          libcacard

          passthrough Enable smartcard passthrough support via sys-apps/pcsc-lite

          libguestfs

          erlang Build Erlang bindings
          fuse Enable image mount support via fuse
          inspect-icons Use media-gfx/icoutils for acces icon file in image and inspect it
          libvirt Use app-emulation/libvirt to manipulate VMs
          systemtap Use dev-util/systemtap to inspect VM via "probes" way

          libpod

          apparmor Enable AppArmor support.
          btrfs Enables dependencies for the "btrfs" graph driver, including necessary kernel flags.
          ostree Enables dependencies for handling of OSTree images.
          rootless Enables dependencies for running in rootless mode.

          libspectrum

          gcrypt Use dev-libs/libgcrypt for low-level crypto of some features, including logfiles.

          libvirt

          apparmor Enable AppArmor support
          dtrace Enable dtrace support via dev-util/systemtap
          firewalld DBus interface to iptables/ebtables allowing for better runtime management of your firewall.
          fuse Allow LXC to use sys-fs/fuse for mount points
          glusterfs Enable GlusterFS support via sys-cluster/glusterfs
          iscsi Allow using an iSCSI remote storage server as pool for disk image storage
          iscsi-direct Allow using libiscsi for iSCSI storage pool backend
          libssh Use net-libs/libssh to communicate with remote libvirtd hosts, for example: qemu+libssh://server/system
          libvirtd Builds the libvirtd daemon as well as the client utilities instead of just the client utilities
          lvm Allow using the Logical Volume Manager (sys-fs/lvm2) as pool for disk image storage
          lxc Support management of Linux Containers virtualisation (app-emulation/lxc)
          macvtap Support for MAC-based TAP (macvlan/macvtap). For networking instead of the normal TUN/TAP.
          nfs Allow using Network File System mounts as pool for disk image storage
          numa Use NUMA for memory segmenting via sys-process/numactl and sys-process/numad
          openvz Support management of OpenVZ virtualisation (openvz-sources)
          parted Allow using real disk partitions as pool for disk image storage, using sys-block/parted to create, resize and delete them.
          pcap Support auto learning IP addreses for routing
          phyp Support IBM HMC / IVM hypervisor via PHYP protocol
          pm-utils Add runtime support for sys-power/pm-utils
          qemu Support management of QEMU virtualisation (app-emulation/qemu)
          rbd Enable rados block device support via sys-cluster/ceph
          vepa Virtual Ethernet Port Aggregator (VEPA) / 802.1Qbg support. Relies on macvtap support.
          virt-network Enable virtual networking (NAT) support for guests. Includes all the dependencies for NATed network mode. Effectively any network setup that relies on libvirt to setup and configure network interfaces on your host. This can include bridged and routed networks ONLY if you are allowing libvirt to create and manage the underlying devices for you. In some cases this requires enabling the 'netcf' USE flag (currently unavailable).
          virtualbox Support management of VirtualBox virtualisation (one of app-emulation/virtualbox or app-emulation/virtualbox-bin)
          wireshark-plugins Build the net-analyzer/wireshark plugin for the Libvirt RPC protocol
          xen Support management of Xen virtualisation (app-emulation/xen)
          zfs Enable ZFS backend storage sys-fs/zfs

          lxc

          apparmor Enable AppArmor support
          cgmanager Enable support for cgroup management using app-admin/cgmanager
          templates Install old style templates through app-emulation/lxc-templates

          lxd

          daemon Build the system daemon, not just the client tool
          dnsmasq 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          tools Build and install optional tools

          nemu

          network-map Adds possibility of exporting network map to SVG
          ovf Adds support for OVA/OVF import
          savevm Adds support for QEMU savevm snapshots (experimental, QEMU must be patched)
          spice Adds Spice protocol support
          vnc-client Adds support for external VNC client

          open-vm-tools

          deploypkg Build deploypkg plugin
          dnet Enable support for nicinfo
          doc Generate API documentation
          fuse Enable vmblock-fuse/vmhgfs-fuse
          grabbitmqproxy Build grabbitmqproxy plugin
          gtkmm Compile with Gtkmm and sigc++ (Recommended)
          multimon Enable multimon (Requires X)
          resolutionkms Build the linux/unix resolutionkms module
          vgauth Build vgauth

          pcem

          networking Enable support for emulation of network cards.

          playonlinux

          winbind Enables support for the winbind auth daemon

          punes

          cg Add support for Nvidia CG Toolkit

          q4wine

          ico Enable ico support via media-gfx/icoutils
          iso Support unprivileged mounting of ISO9660 images via sys-fs/fuseiso
          wineappdb Enable Wine AppDB browser support

          qemu

          accessibility Adds support for braille displays using brltty
          aio Enables support for Linux's Async IO
          alsa Enable alsa output for sound emulation
          capstone Enable disassembly support with dev-libs/capstone
          curl Support ISOs / -cdrom directives vis HTTP or HTTPS.
          fdt Enables firmware device tree support
          glusterfs Enables GlusterFS cluster fileystem via sys-cluster/glusterfs
          gnutls Enable TLS support for the VNC console server. For 1.4 and newer this also enables WebSocket support. For 2.0 through 2.3 also enables disk quorum support.
          iscsi Enable direct iSCSI support via net-libs/libiscsi instead of indirectly via the Linux block layer that sys-block/open-iscsi does.
          jemalloc Enable jemalloc allocator support
          jpeg Enable jpeg image support for the VNC console server
          ncurses Enable the ncurses-based console
          nfs Enable NFS support
          numa Enable NUMA support
          pin-upstream-blobs Pin the versions of BIOS firmware to the version included in the upstream release. This is needed to sanely support migration/suspend/resume/snapshotting/etc... of instances. When the blobs are different, random corruption/bugs/crashes/etc... may be observed.
          png Enable png image support for the VNC console server
          pulseaudio Enable pulseaudio output for sound emulation
          rbd Enable rados block device backend support, see //ceph.newdream.net/wiki/QEMU-RBD
          sdl Enable the SDL-based console
          spice Enable Spice protocol support via app-emulation/spice
          ssh Enable SSH based block device support via net-libs/libssh2
          static Build the User and Software MMU (system) targets as well as tools as static binaries
          static-user Build the User targets as static binaries
          systemtap Enable SystemTAP/DTrace tracing
          500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          Enable the TCG Interpreter which can speed up or slowdown workloads depending on the host and guest CPUs being emulated. In the future it will be a runtime option but for now its compile time.
          usb Enable USB passthrough via dev-libs/libusb
          usbredir Use sys-apps/usbredir to redirect USB devices to another machine over TCP
          vde Enable VDE-based networking
          vhost-net 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          virgl Enable experimental Virgil 3d (virtual software GPU)
          virtfs Enable VirtFS via virtio-9p-pci / fsdev. See //wiki.qemu.org/Documentation/9psetup
          vte Enable terminal support (x11-libs/vte) in the GTK+ interface
          xattr Add support for getting and setting POSIX extended attributes, through sys-apps/attr. Requisite for the virtfs backend.
          xen Enables support for Xen backends
          xfs Support xfsctl() notification and syncing for XFS backed virtual disks.
          xkb Depend on x11-libs/libxkbcommon to build qemu-keymap tool for converting xkb keymaps

          qt-virt-manager

          smartcard Enable smartcard remoting using app-emulation/libcacard

          runc

          ambient Enable support for ambient capabilities set (Requires Linux kernel 4.3 or later).
          apparmor Enable AppArmor support.
          kmem Enable Kernel Memory Accounting.

          runv

          libvirt Enable support for KVM via libvirt
          xen Enable support for the Xen Hypervisor

          spice

          smartcard Enable smartcard remoting using app-emulation/libcacard

          spice-vdagent

          consolekit Use sys-auth/consolekit to determine the master vdagentd in case of multiple running vdagentds (highly recommended)

          vagrant

          virtualbox Use VirtualBox provider.

          vice

          ethernet Enable ethernet emulation
          fullscreen Enable the ability to run fullscreen
          sdlsound Use media-libs/libsdl for sound support
          vte 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          virt-manager

          policykit Enables sys-auth/polkit authentication support, required when using app-emulation/libvirt with PolicyKit authentication
          sasl Depend on the proper libraries needed to connect to SASL-enabled libvirtd instances (e.g. Kerberos-protected instances).

          virt-viewer

          libvirt Support connecting to virtual machines managed by libvirt.
          spice Support connecting to SPICE-enabled virtual machines.
          vnc Support connecting to VNC-enabled virtual machines.

          virt-what

          dmi Use sys-apps/dmidecode to read firmware data

          virtualbox

          dtrace Install dtrace Extension Pack
          headless Build without any graphic frontend
          lvm Build VBoxVolInfo that needs devicemapper from sys-fs/lvm2.
          pax_kernel Apply patch needed for pax enabled kernels.
          sdk Enable building of SDK
          udev Controls installation of special USB udev rules.
          vboxwebsrv Build and install the VirtualBox webservice

          virtualbox-bin

          additions Install Guest System Tools ISO
          chm Install kchmviewer binary to enable online help (in MS CHM format)
          headless Install without any graphic frontend
          rdesktop-vrdp Install the rdesktop client integration
          sdk Enable building of SDK
          vboxwebsrv Install the VirtualBox webservice

          virtualbox-modules

          pax_kernel Apply patch needed for pax enabled kernels

          vkd3d

          spirv-tools Enable SPIRV shader debugging support using dev-util/spirv-tools

          wine-d3d9

          capi Enable ISDN support via CAPI
          custom-cflags Bypass strip-flags; use at your own peril
          d3d9 Apply highly experimental patches for Gallium Nine support. This patch may break some applications.
          dos Pull in games-emulation/dosbox to run DOS applications
          gecko Add support for the Gecko engine when using iexplore
          gssapi Use GSSAPI (Kerberos SSP support)
          gstreamer Use media-libs/gstreamer to provide DirectShow functionality;
          mono Add support for .NET using Wine's Mono add-on
          netapi Use libnetapi from net-fs/samba to support Windows networks in netapi32.dll
          opencl Enable OpenCL support
          osmesa Add support for OpenGL in bitmaps using libOSMesa
          pcap 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          perl Install helpers written in perl (winedump/winemaker)
          prelink Run prelink on DLLs during build; For 沙巴体育 hardened, do not disable if you do not know what this means as it can break things at runtime
          realtime Pull in sys-auth/rtkit for low-latency pulseaudio support
          run-exes Use Wine to open and run .EXE and .MSI files
          samba Add support for NTLM auth. See: //web.archive.org/web/20160108123008///wiki.winehq.org:80/NtlmAuthSetupGuide and //web.archive.org/web/20150906013746///wiki.winehq.org/NtlmSigningAndSealing (these pages are not currently in the updated WineHQ Wiki).
          sdl Add support for gamepad detection using SDL
          udev Use virtual/libudev to provide plug and play support
          vkd3d Use app-emulation/vkd3d to provide Direct3D 12 support
          vulkan Enable Vulkan drivers

          wine-staging

          capi Enable ISDN support via CAPI
          custom-cflags Bypass strip-flags; use at your own peril
          dos Pull in games-emulation/dosbox to run DOS applications
          faudio Pull in app-emulation/faudio to provide XAudio2 functionality
          gecko Add support for the Gecko engine when using iexplore
          gssapi Use GSSAPI (Kerberos SSP support)
          gstreamer Use media-libs/gstreamer to provide DirectShow functionality;
          mono Add support for .NET using Wine's Mono add-on
          netapi Use libnetapi from net-fs/samba to support Windows networks in netapi32.dll
          opencl Enable OpenCL support
          osmesa Add support for OpenGL in bitmaps using libOSMesa
          pcap 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          perl Install helpers written in perl (winedump/winemaker)
          pipelight Apply Wine-Staging patches for Pipelight/Silverlight support
          prelink Run prelink on DLLs during build; For 沙巴体育 hardened, do not disable if you do not know what this means as it can break things at runtime
          realtime Pull in sys-auth/rtkit for low-latency pulseaudio support
          run-exes Use Wine to open and run .EXE and .MSI files
          samba Add support for NTLM auth. See: //web.archive.org/web/20160108123008///wiki.winehq.org:80/NtlmAuthSetupGuide and //web.archive.org/web/20150906013746///wiki.winehq.org/NtlmSigningAndSealing (these pages are not currently in the updated WineHQ Wiki).
          sdl Add support for gamepad detection using SDL
          staging Apply Wine-Staging patches for advanced feature support that haven't made it into upstream Wine yet
          themes Support GTK+:3 window theming through Wine-Staging
          udev Use virtual/libudev to provide plug and play support
          vkd3d Use app-emulation/vkd3d to provide Direct3D 12 support
          vulkan Enable Vulkan drivers

          wine-vanilla

          capi Enable ISDN support via CAPI
          custom-cflags Bypass strip-flags; use at your own peril
          dos Pull in games-emulation/dosbox to run DOS applications
          faudio Pull in app-emulation/faudio to provide XAudio2 functionality
          gecko Add support for the Gecko engine when using iexplore
          gssapi Use GSSAPI (Kerberos SSP support)
          gstreamer Use media-libs/gstreamer to provide DirectShow functionality;
          mono Add support for .NET using Wine's Mono add-on
          netapi Use libnetapi from net-fs/samba to support Windows networks in netapi32.dll
          opencl Enable OpenCL support
          osmesa Add support for OpenGL in bitmaps using libOSMesa
          pcap 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          perl Install helpers written in perl (winedump/winemaker)
          prelink Run prelink on DLLs during build; For 沙巴体育 hardened, do not disable if you do not know what this means as it can break things at runtime
          realtime Pull in sys-auth/rtkit for low-latency pulseaudio support
          run-exes Use Wine to open and run .EXE and .MSI files
          samba Add support for NTLM auth. See: //web.archive.org/web/20160108123008///wiki.winehq.org:80/NtlmAuthSetupGuide and //web.archive.org/web/20150906013746///wiki.winehq.org/NtlmSigningAndSealing (these pages are not currently in the updated WineHQ Wiki).
          sdl Add support for gamepad detection using SDL
          udev Use virtual/libudev to provide plug and play support
          vkd3d Use app-emulation/vkd3d to provide Direct3D 12 support
          vulkan Enable Vulkan drivers

          winetricks

          rar Pull in app-arch/unrar for extraction of rar-compressed game files

          x48

          readline Enables support for libreadline

          xe-guest-utilities

          xenstore Use xenstore binaries bundled by Citrix instead of building app-emulation/xen-tools

          xen

          efi Adds efi boot support, requires LDFLAG -melf_x86_64 for amd64
          flask Enable the Flask XSM module from NSA

          xen-tools

          api Build the C libxenapi bindings
          flask Enable the Flask XSM module from NSA
          hvm Enable support for hardware based virtualization (VT-x,AMD-v)
          ipxe Enable ipxe support
          ocaml Enable support for the ocaml language
          ovmf Enable support to boot UEFI guest vm, needed by hvm
          pam Enable pam support
          pygrub Install the pygrub boot loader
          qemu Enable IOEMU support via the use of qemu-dm
          qemu-traditional Build the old qemu traditional device model (useful only if you cannot change to the new device model e.g. Windows VMs)
          rombios Enable rombios support, needed by ipxe
          screen Enable support for running domain U console in an app-misc/screen session
          system-ipxe Using sys-firmware/ipxe instead of the bundled one
          system-qemu Using app-emulation/qemu instead of the bundled one
          system-seabios Using sys-firmware/seabios instead of the bundled one

          xtrs

          ls-dos Install LS-DOS disk images for Model 4P

          app-eselect

          eselect-php

          fpm Enable the FastCGI Process Manager SAPI

          app-forensics

          afflib

          fuse Enable extra fuse thingies
          qemu Enable qemu stuff
          s3 Enable support for Amazon S3

          aide

          e2fs Enable support for checking file attributes on ext2/ext3/ext4 filesystems
          prelink Bypass prelinking when calculating checksums

          chkrootkit

          cron Install cron script for weekly rootkit scans

          libewf

          bfio Enables libbfio for chaining file in file handling
          fuse Enable fuse support for ewfmount
          uuid Enable UUID support in the ewftools

          openscap

          gconf Build the gconf independant probes
          nss Prefer NSS over libgcrypt as the crypto engine
          rpm Compiles the RPM probes
          sce Enables Script Check Engine (SCE) support
          sql Build the sql independant probes

          quickfuzz

          archs support archive formats
          codes support cource code formats
          docs support document formats
          imgs support image formats
          media support media formats
          net support networking formats
          pki support PKI formats

          sleuthkit

          aff Enable extra aff formats
          ewf Enable libewf support

          app-i18n

          anthy

          canna-2ch Enable support for app-dicts/canna-2ch

          canna

          canuum Build canuum

          fcitx

          autostart Enable XDG-compatible autostart of Fcitx
          enchant Enable Enchant backend (using app-text/enchant) for spelling hinting
          gtk2 Install input method module for GTK+ 2
          gtk3 Install input method module for GTK+ 3
          opencc Enable OpenCC engine (using app-i18n/opencc) for converter between Simplified Chinese and Traditional Chinese
          pango Enable support for x11-libs/pango
          table Install table input methods for Simplified Chinese

          fcitx-libpinyin

          dictionary-manager Install dictionary manager

          fcitx-rime

          configuration_tool Install configuration tool

          fcitx-unikey

          macro-editor Install macro editor

          freewnn

          uum Build uum

          ibus

          emoji Enable support for Emoji
          gconf Enable support for gnome-base/gconf
          gtk2 Enable support for x11-libs/gtk+:2
          unicode Enable support for Unicode choice

          ibus-chewing

          gconf Enable support for gnome-base/gconf

          ibus-handwrite

          zinnia Enable support for app-i18n/zinnia

          ibus-libpinyin

          boost Compile against dev-libs/boost libraries
          opencc Enable support for app-i18n/opencc

          ibus-m17n

          gtk2 Build with x11-libs/gtk+:2 instead of x11-libs/gtk+:3

          ibus-pinyin

          boost Enable support for dev-libs/boost

          ibus-unikey

          gtk2 Enable support for x11-libs/gtk+:2

          im-chooser

          gtk2 Build with x11-libs/gtk+:2 instead of x11-libs/gtk+:3
          xfce Enable support for XFCE panel

          imsettings

          gconf Enable support for gnome-base/gconf
          gtk2 Build with x11-libs/gtk+:2 instead of x11-libs/gtk+:3
          xfconf Enable support for xfce-base/xfconf

          mozc

          fcitx4 Enable support for app-i18n/fcitx 4
          gui Install graphical user interface tool (mozc_tool)
          handwriting-tegaki Use handwriting recognition model from app-i18n/tegaki-zinnia-japanese
          handwriting-tomoe Use handwriting recognition model from app-i18n/zinnia-tomoe
          ibus Enable support for app-i18n/ibus
          renderer Enable native candidate window

          pyzy

          boost Enable support for dev-libs/boost
          doc Generate API documentation
          opencc Enable support for app-i18n/opencc

          rime-data

          extra Install extra packages

          scim

          gtk3 Enable support for x11-libs/gtk+:3

          scim-anthy

          gtk3 Enable support for x11-libs/gtk+:3
          kasumi Use Anthy dictionary maintenance tool (app-dicts/kasumi)

          scim-sunpinyin

          gtk3 Enable support for x11-libs/gtk+:3

          tomoe

          hyperestraier Enable support for app-text/hyperestraier

          translate-shell

          tts Enable text-to-speech support

          uim

          anthy Enable support for app-i18n/anthy
          eb Enable support for dev-libs/eb
          gtk2 Enable support for x11-libs/gtk+:2
          skk Enable support for app-i18n/skk-jisyo

          app-laptop

          hdapsd

          libconfig Require dev-libs/libconfig to allow the daemon to read a configuration file at startup

          ibam

          gkrellm 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          laptop-mode-tools

          apm Add APM (Advanced Power Management) support

          pbbuttonsd

          ibam Enable support for Intelligent Battery Monitoring
          macbook Enable support for the Macbook and Macbook Pro

          thinkfan

          atasmart include libatasmart support to get disc temperature
          nvidia allow thinkfan to read GPU temperature from the proprietary nVidia driver
          yaml use YAML format for config file

          tp_smapi

          hdaps Install a compatible HDAPS module

          app-leechcraft

          lc-azoth

          acetamide Build Acetamide, the IRC protocol support
          adiumstyles Build support for Adium styles
          astrality Build Astrality, support for protocols provided by Telepathy
          autoidler Build support for automatic status changing according to user idle time
          autopaste Build Autopaste for pasting long texts to pastebins
          birthdaynotifier Build Birthday Notifier for you to not forget about birthdays of your contacts.
          chathistory Build ChatHistory which stories chat history
          depester Build Depester which enables to ignore MUC participants
          embedmedia Build EmbedMedia for embedding flash videos and images directly into chat windows
          herbicide Build Herbicide, a basic antispam plugin
          hili Build HiLi which allows to customize highlight settings in MUCs
          isterique Build Isterique plugin for neutralizing excessive caps lock usage
          juick Build plugin for the Juick.com microblogging service
          keeso Build plugin for changing text into SoMEtHInG lIKe THiS
          lastseen Build plugin for client-side recording of the last online/available time
          media Enable media calls
          metacontacts Build plugin for metacontacts support
          murm Build Murm, the VKontakte messaging support via their native API (instead of XMPP)
          nativeemoticons Build support for native Azoth's emoticons packs
          otroid Build OTRoid, plugin for the Off-the-Record deniable encryption system
          sarin Build Sarin, Tox protocol support module. Please add mva overlay to use net-libs/tox
          shx Build shell command executor plugin
          standardstyles Build support for standard Azoth styles engine
          vader Bulid Vader, the MRIM (Mail.Ru Agent) protocol support plugin
          velvetbird Build support for protocols provided by libpurple
          woodpecker Build Woodpecker, the Twitter client plugin
          xtazy Build Xtazy for publishing currently playing tune

          lc-blasq

          deathnote Support LiveJournal FotoBilder service
          rappor Support VKontakte service
          spegnersi Support Flickr service
          vangog Support Picasa service

          lc-blogique

          hestia Allows one to keep a local blog
          metida Support for the LiveJournal blogging platform

          lc-core

          qwt Support for QML plotting item through x11-libs/qwt

          lc-gmailnotifier

          notify Pull in a plugin to show notifications from GMail Notiifer
          quark Pull in a plugin to show GMail Notifier's quark

          lc-lmp

          fradj Build FrAdj, the equalizer effect module
          graffiti Build media tags editor plugin
          mp3tunes Build plugin for supporting the mp3tunes.com music locker service
          mpris Enable MPRIS support
          potorchu Enable the projectM-based visualization effects module for LMP

          lc-monocle

          fb2 Enable support for FictionBook format
          mobi Enable support for MOBI format

          lc-musiczombie

          acoustid Use media-libs/chromaprint for acoustic fingerprinting

          lc-netstoremanager

          dropbox Build Dropbox storage backend
          googledrive Build Google Drive storage backend

          lc-poshuku

          autosearch Provide automatic search suggestions for Poshuku.
          cleanweb Build CleanWeb for ad blocking compatible with Firefox's AdBlock+.
          dcac Build color inverter module providing a night mode.
          fatape Build FatApe, GreaseMonkey userscripts support layer.
          filescheme Build FileScheme for accessing local URLs.
          foc Build FOC for Flash-on-Click functionality.
          fua Build FUA for faking user agents for different hosts.
          keywords Build Keywords for adjusting search shortcuts.
          onlinebookmarks Build OnlineBookmarks for syncing bookmarks with social bookmarking services like Read It Later.
          qrd Build module for displaying the QR code of a web page.
          speeddial Build SpeedDial module.
          webengine Build WebEngine- (that is, Chromium-)based rendering backend.

          lc-secman

          exposecontents Build the GUI for viewing the stored data.

          leechcraft-meta

          de Install components, that allow using Leechcraft as Desktop Environment

          app-metrics

          collectd

          contrib Install user-contributed files in the doc directory
          filecaps When set collectd daemon will have set required capabilities to run most plugins even if run as unprivileged user
          java Must be set (workaround for java-pkg-opt-2 eclass limitation) when you want java or genericjmx plugin
          udev Enable optional udev usage in disk plugin; Required for smart plugin
          xfs Enable optional capability to filter on XFS file system in df plugin; Requires XFS headers from sys-fs/xfsprogs

          app-misc

          anki

          recording Enable support for audio recording
          sound Enable support for adding sound to cards

          binwalk

          graph Enable support for generating entropy graphs

          blink1

          mini-tool Build and install command-line mini-tool blink1-mini-tool (normally used for embedded devices)
          server Build and install REST API server (currently hard-coded to TCP port 8080)
          tool Build and install command-line tool blink1-tool

          byobu

          screen Use app-misc/screen as the default backend

          ca-certificates

          cacert Include root certificates from CAcert (//www.cacert.org/) and Software in the Public Interest (//www.spi-inc.org/)

          carbon-c-relay

          lz4 add support for LZ4 compressed transport
          oniguruma use dev-libs/oniguruma as regex implementation
          pcre2 use dev-libs/libpcre2 as regex implementation
          snappy add support for Snappy compressed transport

          ddccontrol

          pci enable direct PCI memory access (the setuid ddcpci util)

          ddcutil

          drm Use x11-libs/libdrm for more verbose diagnostics.
          usb-monitor Adds support for monitors attached via USB.
          user-permissions Adds a udev rules to allow non-root users in the i2c group to access the /dev/i2c-* devices. If usb-monitor is selected, users will need to be added to the video group to access the USB monitor. Otherwise, only root will be able to use ddcutil.

          digitemp

          ds2490 Build support for the ds2490 sensor
          ds9097 Build support for the ds9097 sensor
          ds9097u Build support for the ds9097u sensor

          elasticsearch

          x-pack Enable additional features (may need a license)

          emelfm2

          ansi Add support for ANSI escape sequences
          gtk3 Use x11-libs/gtk+:3 instead of x11-libs/gtk+:2

          g810-led

          hidapi Use dev-libs/hidapi instead of virtual/libusb for talking to the device (advertised to be faster)

          gcstar

          stats Enable statistics reporting
          tellico Enable support for kde-misc/tellico files

          geoclue

          modemmanager Enable geolocation through 3G or GPS enabled hardware through net-misc/modemmanager.
          zeroconf Enable retrieval of GPS location from Android devices with //wiki.gnome.org/Apps/GeoclueShare

          gourmet

          i18n Enable support for i18n through elib.intl
          ipython Enable support for the interactive Python console plugin
          pdf Enable export to PDF
          print Enable pretty Python printing
          spell Enable support for the spell check plugin
          web Enable support for the web import plugin

          gramps

          geo Enable rendering of geographical data using sci-geosciences/osm-gps-map
          rcs Adds support for family tree archives via dev-vcs/rcs
          reports All external software that is needed for graphical reports will be installed

          graphlcd-base

          fontconfig Add support for media-libs/fontconfig font names.
          freetype Add support for media-libs/freetype.
          g15 Add support for app-misc/g15daemon, used by the Logitech G15 keyboard.
          graphicsmagick Add support for media-gfx/graphicsmagick.
          imagemagick Add support for media-gfx/imagemagick.

          irtrans-irserver

          mono Enable mono support

          jq

          oniguruma Use dev-libs/oniguruma for regular expression support

          kryoflux-dtc

          demos Install example floppy game files.
          fast-firmware Install fast firmware instead of slow firmware.
          gui Install the Kryoflux GUI

          lcd4linux

          apm Enable the APM plugin.
          asterisk Enable the Asterisk plugin.
          button-exec Enable the Button plugin, to execute something on keypress.
          cpuinfo Enable the cpuinfo plugin.
          dbus Enable the dbus plugin.
          diskstats Enable the diskstats plugin.
          dmalloc Enable dmalloc for debugging.
          dvb Enable support for the DVB plugin.
          event Enable the event plugin.
          exec Enable the exec plugin, to read output from external programs.
          fifo Enable the FIFO (First-In, First-Out) plugin.
          file Enable the file plugin, to read from input from files.
          gps Enable the gps plugin, for reading gps coordinates.
          hddtemp Enable the hddtemp plugin, to read from the hddtemp daemon.
          huawei Enable the huawei plugin, to read from a huawei device.
          i2c-sensors Enable the i2c_sensors plugin, to read sensor data.
          iconv Enable the iconv plugin, to convert between encodings.
          isdn Enable the isdn plugin, to get information about ISDN.
          kvv Enable the kvv plugin, to get realtime train schedule from the Karlsruher Verkehrsverbund.
          loadavg Enable the loadavg plugin, to get stats load
          meminfo Enable the meminfo plugin, to get memory statistics.
          mpd Enable the mpd plugin, to read from the Music Player Daemon.
          mpris-dbus Enable the mpris plugin, to read data via dbus for mpris.
          mysql Enable the mysql plugin, to get mysql database information.
          netdev Enable the netdev plugin, to get interface statistics.
          netinfo Enable the netinfo plugin, to get more interface statistic.
          outb Enable raw i/o access.
          pop3 Enable the pop3 plugin, to get notified about new mails.
          proc-stat Enable the proc_stat plugin, to read data from the proc file system.
          python Enable support for dev-lang/python and enable the python plugin, to execute own python scripts.
          qnaplog Enable the qnaplog plugin, to read a log from a QNAP device.
          raspi Enable the raspi plugin, to read sensor data from a Raspberry Pi.
          sample Enable the sample plugin.
          statfs Enable the statfs plugin, to get statistics about the file system.
          uname Enable the uname plugin, to get the output of uname.
          uptime Enable the uptime plugin.
          w1retap Enable the w1retap plugin.
          wireless Enable the wireless plugin, to get wireless statistics.

          lcdproc

          ethlcd Enable support for ethlcd in the hd44780 driver.
          extra-charmaps Enable extra language specific charmaps.
          freetype Enable support for media-libs/freetype in the glcd driver.
          menu Enable menu support in the lcdproc client.
          nfs Display NFS filesystem stats in the lcdproc client.
          png Enable support for media-libs/libpng in the glcd driver.
          samba Display SMBFS filesystem stats in the lcdproc client.
          test-menu Enable test menu support for the lcdproc server.

          lirc

          audio Support using an audio device connected to an IR receiver
          devinput Support the devinput input device
          ftdi Support FTDI devices
          gtk Include GTK support which enables the use of lirc-setup
          inputlirc Add a dependency on app-misc/inputlircd
          uinput Enable support for uinput

          mc

          edit Compile and install the mcedit application
          sftp Add support for sftp (uses net-libs/libssh2 for it).
          slang Use sys-libs/slang instead of sys-libs/ncurses.
          xdg Toggles mc's config dir location. Enable for $XDG_CONFIG_HOME/mc, disable for $HOME/.mc

          mosquitto

          bridge Enable bridge support in the MQTT broker.
          persistence Store messages and subscriptions to a file.
          srv Include SRV lookup support.
          websockets Support the WebSocket protocol.

          muttprint

          doc Builds documentation

          neofetch

          X Enable support for detecting DEs, WMs, screen resolutions, and showing images from an X terminal

          note

          general Add support for ascii flatfile backend
          text Add support for text backend

          openastro

          jpeg Enable exporting Astrological Charts to jpeg
          png Enable exporting Astrological Charts to png

          pax-utils

          python Install a more powerful/faster version of lddtree

          recoll

          camelcase Enable indexing for camelCase sentences and words
          chm Enable CHM file support via dev-python/pychm
          inotify Use the Linux Kernel notification subsystem for monitoring file alterations in realtime
          session Stop monitoring file alterations when X11 session terminates
          webengine Use dev-qt/qtwebengine for fancy result list display

          rlwrap

          debug Enable debug

          screen

          multiuser Enable multiuser support (by setting correct permissions)
          nethack Express error messages in nethack style
          utmp Include utmp support

          screenfetch

          X Use the media-gfx/scrot package to take screenshots

          skim

          tmux Install sk-tmux script to run skim in a tmux pane
          vim Install vim plugin for skim

          sphinx

          id64 use 64-bit document and word IDs
          mariadb Add mariadb database support
          re2 use the dev-libs/re2 regular expression library
          stemmer Enable language stemming support

          task

          sync Enable "task sync" support

          tmux

          utempter Include libutempter support

          towitoko

          moneyplex Makes libtowitoko work for the moneyplex home banking software

          tracker

          miners Install the app-misc/tracker-miners package for actual data mining support for tracker
          stemmer Add word stemming via dev-libs/snowball-stemmer.

          tracker-miners

          cue Enable cue sheet parsing
          gsf Enable gnome-extra/libgsf based data extractor and for ODT.
          iptc Enable extraction of IPTC data from pictures
          iso Enable extraction of metadata from ISO disk images
          playlist Add support for playlists
          xps Add support for XPS file format through app-text/libgxps.

          unfoo

          minimal Do not install all support archive binaries

          vcontrold

          man Build the manpages
          vclient Build the vclient helper program to talk to vcontrold
          vsim Build the vsim helper program (simulates the heating's answers, for development and debugging)

          vifm

          developer Enable features of interest to developers
          extended-keys Support for extended keys (arrows, home etc)
          gtk Use gtk+ to determine mimetypes
          vim Install the vifm vim plugin and vim-compatible documentation

          worker

          avfs Enable support for sys-fs/avfs

          workrave

          mate Add support for MATE panel
          xfce Add support for XFCE panel

          zygrib

          maps Installs additional GSHHS maps for high resolution coastline data and cities

          app-mobilephone

          adb-sync

          channel Install the adb-channel script

          gammu

          bluetooth Enables bluetooth support
          curl Enables curl support
          irda Enables infrared support
          mysql Use mysql for data storage
          nls Enable native language support
          odbc Use ODBC as DB connector
          postgres Use PostgreSQL for data storage
          usb Enable USB suport

          gnokii

          ical Enable support for dev-libs/libical
          irda Enable infrared support
          pcsc-lite Enable smartcard support with sys-apps/pcsc-lite
          sms Enable SMS support (build smsd)

          smstools

          stats Enable statistic reporting

          app-office

          abiword

          collab Enable collaborative editing plugin
          goffice Enable goffice plugin
          grammar Enable grammar checking via dev-libs/link-grammar
          map Enable world map support through media-libs/libchamplain
          math Enable support for x11-libs/gtkmathview
          ots Enable Text Summarizer plugin
          plugins Enable plugins build (see //www.abisource.com/wiki/PluginMatrix for more information). If your file cannot be opened due lack of support, try enabling this.
          redland Enables support redland and raptor libs.
          thesaurus Enable thesaurus support
          wordperfect Enable wordperfect file support via app-text/libwpd

          calligra

          activities Enable kactivities support
          charts Build chartshape plugin for creating business charts with dev-libs/kdiagram
          gemini Enable tablet and 2:1 devices support
          import-filter Enable support for various import filter file formats like WordPerfect, Visio and Apple Keynote
          lcms Build colorengine plugins using media-libs/lcms
          okular Enable bindings for kde-apps/okular
          phonon Build stage/eventplugins and videoshape plugin using media-libs/phonon
          spacenav Enable support for the 3Dconnexion spacenav input device via dev-libs/libspnav

          calligraplan

          activities Enable kactivities support
          holidays Enable kde-frameworks/kholidays integration
          kwallet Enable access to encrypted OpenDocument files with kde-frameworks/kwallet storage

          glabels

          barcode Enable barcode support through external libraries.

          gnucash

          aqbanking Connect to some internet banks via AqBanking
          chipcard Enable support for chipcard reading and processing.
          gui Enable graphic interface (needs net-libs/webkit-gtk:4 and x11-libs/gtk+:3)
          quotes Enable Online Stock Quote retrieval
          register2 Use the new register (Experimental)

          gnumeric

          libgda Enable database support through gnome-extra/libgda.
          perl Enable perl plugin loader.
          python Enable python plugin loader.

          grisbi

          goffice enable goffice graphic support

          kexi

          experimental Enable features deemed experimental by upstream
          marble Enable displaying of maps using kde-apps/marble
          mdb Enable support for Microsoft Access database
          webkit Enable web form designer widget using dev-qt/qtwebkit

          kmymoney

          activities Enable kde-frameworks/kactivities integration
          addressbook Enable kde-apps/akonadi contact integration
          hbci Enable HBCI support using net-libs/aqbanking
          holidays Enable kde-frameworks/kholidays integration
          quotes Enable Online Stock Quote retrieval
          weboob Enable import of online banking transactions extracted by www-client/weboob

          kraft

          pim Enable support for KDE PIM resources integration

          libreoffice

          coinmp Use sci-libs/coinor-mp as alternative solver
          googledrive Enable support for remote files on Google Drive
          gtk2 Enable legacy gtk2 frontend
          mariadb Prefer mariadb connector over mysql connector
          odk Build the Office Development Kit
          pdfimport Enable PDF import via the Poppler library

          libreoffice-l10n

          offlinehelp Install help files locally instead of using the LibreOffice Wiki

          lyx

          aspell Add support for aspell spellchecking
          dia Add support for diagrams (app-office/dia)
          docbook Add support for docbook export
          dot Add support for DOT import (media-gfx/graphviz)
          enchant Add support for enchant spellchecking wrapper (both aspell and hunspell can be used by LyX).
          gnumeric Add support for importing Gnumeric/OpenOffice/MS Excel spreadsheets into LyX.
          html Add support for HTML import
          hunspell Add support for spellchecking based on hunspell and reuse system-wide OpenOffice dictionaries. This also enable thesaurus dictionaries not accessible via aspell.
          monolithic-build This should speed up compilation significantly when you have enough RAM (> 600 MB)
          rcs Add support for revision control via dev-vcs/rcs
          rtf Add support for RTF import/export packages

          magicpoint

          contrib Install additional contributed scripts

          orage

          clock-panel-plugin Build the clock plugin for the XFCE panel

          scribus

          boost Enable support for Boost based enhancement
          hunspell Enable support for spell checking with app-text/hunspell
          minimal Don't install headers (only required for e.g. plug-in developers)
          osg 3D redering via dev-games/openscenegraph
          scripts Install the scripts
          templates Document tamplates
          tk Install tk based scripts e.g. FontSample.py

          skrooge

          activities Enable kactivities support
          designer Build plugins for dev-qt/designer
          webkit Build with dev-qt/qtwebkit instead of dev-qt/qtwebengine

          texmacs

          netpbm Add support for media-libs/netpbm

          texstudio

          video Use phonon for video embedding

          app-pda

          barry

          boost Enable boost support
          gui Install the GUI backup tool

          gtkpod

          clutter Enable clutter support for displaying coverart

          app-portage

          conf-update

          colordiff Use colors when displaying diffs (app-misc/colordiff)
          libressl Enable SSL connections and crypto functions using dev-libs/libressl

          eix

          debug Build with upstream's CXXFLAGS/LDFLAGS for debugging support; not recommended for normal use.
          doc Create description of the eix cache file additionally in html format
          sqlite Compile in support for portage's sqlite backend; to actually use it you need additional configuration of portage and eix

          g-sorcery

          bson Support BSON file format for package DB

          gemato

          blake2 Install dependencies needed for BLAKE2 hash functions
          gpg Install dependencies needed for OpenPGP signature verification support
          sha3 Install dependencies needed for SHA3 hash functions
          tools Install additional utilities (benchmarks, hash testing tools, fast Manifest generators) to /usr/share/gemato.

          grs

          server Install all the tools building systems

          layman

          bazaar Support dev-vcs/bzr based overlays
          cvs Support dev-vcs/cvs based overlays
          darcs Support dev-vcs/darcs based overlays
          g-sorcery Support app-portage/g-sorcery based overlays
          git Support dev-vcs/git based overlays
          gpg Support app-crypt/gnupg signed overlays lists and manifests
          mercurial Support dev-vcs/mercurial based overlays
          squashfs Support mounting squashfs image overlays locally read-only
          subversion Support dev-vcs/subversion based overlays
          sync-plugin-portage Install the sys-apps/portage sync module

          pfl

          network-cron Adds a cron job which does a weekly submit of the package database

          portage-utils

          qmanifest Build qmanifest applet, this adds additional dependencies for GPG, OpenSSL and BLAKE2B hashing
          qtegrity Build qtegrity applet, this adds additional dependencies for OpenSSL

          tatt

          templates Install template scripts to be used with tatt

          app-shells

          autojump

          ipython Add support for dev-python/ipython

          bash

          bashlogger Log ALL commands typed into bash; should ONLY be used in restricted environments such as honeypots
          mem-scramble Build with custom malloc/free overwriting allocated/freed memory
          net Enable /dev/tcp/host/port redirection
          plugins Add support for loading builtins at runtime via 'enable'

          bash-completion

          eselect 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          dash

          vanilla Support echo -n, and enable echo -e all the time (unsupported)

          mksh

          lksh variant that uses POSIX-compliant arithmetics with the host “long” data type and is automatically in POSIX mode when called as /bin/sh

          pdsh

          rsh This allows the use of rsh (remote shell) and rcp (remote copy) for authoring websites. sftp is a much more secure protocol and is preferred.

          shish

          diet Use dev-libs/dietlibc

          app-text

          asciidoc

          highlight Enable source code highlighting

          atril

          caja Enable property page extension in mate-base/caja
          dvi Enable build-in DVI viewer
          epub Enable build-in DVI viewer using net-libs/webkit-gtk
          t1lib Enable the Type-1 fonts for the build-in DVI viewer (media-libs/t1lib)
          xps Enable XPS viewer using app-text/libgxps

          blogc

          git Build blogc-git-receiver tool
          httpd Build blogc-runserver tool
          make Build blogc-make tool

          cb2bib

          webengine Use dev-qt/qtwebengine instead of dev-qt/qtwebkit

          coolreader

          wxwidgets Use x11-libs/wxGTK instead of Qt5

          crm114

          mew Add support for using the mewdecode mime decoder (app-emacs/mew)
          mimencode Add support for using the mimencode mime (net-mail/metamail)
          normalizemime Add support for using the normalizemime (mail-filter/normalizemime)

          dbacl

          interactive Enable the interactive mailinspect ability

          dblatex

          inkscape Use inkscape to convert SVG. Disable to use gnome-base/librsvg instead.

          dictd

          judy Build Judy-based (dev-libs/judy) plugin implementing fast "exact" and especially "lev" strategies
          minimal Don't build server but dict client, dictzip and dictfmt only.

          docbook-sgml-utils

          jadetex Add support for app-text/jadetex (for processing tex files produced by the TeX backend of Jade)

          docbook-xsl-ns-stylesheets

          ruby Install the Ruby-based dbtoepub script; requires an interpreter compatible with app-eselect/eselect-ruby.

          docbook-xsl-stylesheets

          ruby Install the Ruby-based dbtoepub script; requires an interpreter compatible with app-eselect/eselect-ruby.

          ebook-tools

          lit2epub Install lit2epub script

          editorconfig-core-c

          cli Install command line interface.

          enchant

          aspell Adds support for app-text/aspell spell checker
          hunspell Adds support for app-text/hunspell spell checker

          evince

          dvi Enable the built-in DVI viewer
          nautilus Enable property page extension in gnome-base/nautilus
          postscript Enable support for PostScript and Adobe Illustrator documents with app-text/libspectre
          spell Enable inline spell check for annotations via app-text/gspell
          t1lib Enable the Type-1 fonts for the built-in DVI viewer (media-libs/t1lib)
          xps Enable XPS viewer using app-text/libgxps

          getxbook

          ocr Use app-text/tesseract for optical character recognition

          ghostscript-gpl

          unicode Add support for unicode passwords via net-dns/libidn

          groonga

          abort Enable query abortion
          benchmark Build benchmark programs
          dynamic-malloc-change Allow dynamic memory allocation change for testing
          exact-alloc-count Atomic counting for memory alloc count
          fmalloc Make memory allocation failed in specified condition for debug
          futex Use futex
          libevent Enable dev-libs/libevent used for suggestion
          mecab Use app-text/mecab for morphological analysis
          msgpack Enable dev-libs/msgpack used for suggestion
          nfkc Use nfkc based utf8 normalization
          sphinx Enable document generation by app-misc/sphinx
          uyield Build for detecting race conditions
          zeromq Enable net-libs/zeromq used for suggestion

          hyperestraier

          mecab Enable app-text/mecab support for Estraier

          kbibtex

          webengine Use dev-qt/qtwebengine for HTML previews
          zotero Enable support for synchronisation with zotero.org web service

          lcdf-typetools

          kpathsea Enable integration with kpathsea search library (TeX related)

          libebook

          tools Build file conversion tools

          libmwaw

          tools Build file conversion tools

          libqxp

          tools Build file conversion tools

          libstaroffice

          tools Build conversion tools
          zlib Enable support for compressed data

          libwpd

          tools Build file conversion tools

          libwps

          tools Build file conversion tools

          mathtex

          png Generate png images by default instead of gif

          msort

          heap Use heap instead of alloca()
          icu Use dev-libs/icu instead of dev-libs/libutf8proc.
          libuninum Use dev-libs/libuninum for conversion.

          pandoc

          embed-data-files Embed data files in binary for relocatable executable.
          http-conduit Enable downloading of resources over https.
          https Enable support for downloading of resources over https.
          make-pandoc-man-pages Build program to regenerate pandoc man pages from README.
          network-uri Get Network.URI from the network-uri package.
          trypandoc Build trypandoc cgi executable.
          weigh-pandoc Build weigh-pandoc to measure memory usage.

          pastebinit

          crypt Install pbputs for gpg-encrypted pastes

          pdfgrep

          unac Removing accents and ligatures before search

          pelican

          markdown Markdown support

          podofo

          boost Add support for boost
          tools Build and install commandline tools.

          poppler

          nss Enable signatures handling with dev-libs/nss
          utils Install command-line PDF converters and various utilities.

          qpdf

          perl Install fix-qdf tool (for reverting PDF edits) written in perl

          qpdfview

          fitz Use experimental fitz rendering, provided by app-text/mupdf, instead of poppler
          synctex Add support for searching TeX sources

          robodoc

          examples Installs usage examples in /usr/share for Perl

          sdcv

          darkterm Improve readability of color output on terminals with dark background.

          sgmltools-lite

          jadetex Add support for app-text/jadetex (for processing tex files produced by the TeX backend of Jade)

          sigil

          plugins Installed needed Python packages for using Sigil plugins
          system-mathjax Use the system-wide dev-libs/mathjax instead of bundled

          stardict

          advertisement Enable stardict advertisements plugin
          cal Enable calendar support using cal program
          dictdotcn Enable dict.cn network plugin (for Chinese language)
          espeak Enable text to speech synthesizer plugin using app-accessibility/espeak engine
          flite Enable text to speech synthesizer plugin using app-accessibility/flite engine
          fortune Enable plugin to read fortune messages using games-misc/fortune-mod. You may consider installing games-misc/fortune-mod-all to get all fortune messages.
          gucharmap Enable plugin for unicode symbols description using gnome-extra/gucharmap
          htmlparse Enable plugin to parse dictionaries with html content
          info Enable plugin to read info pages
          man Enable plugin to read manual pages
          powerwordparse Enable plugin to parse powerword dictionaries
          pronounce Install WyabdcRealPeopleTTS package (it is just many .wav files) to make StarDict pronounce English words
          qqwry Enable QQWry plugin, which provides information (in Chinese language) about geographical positions, owner, etc. for IP addresses
          tools Build and install dictionary management tools and converters from various dictionary formats
          updateinfo Enable plugin to check for stardict updates
          wikiparse Enable plugin to parse dictionaries in wikimedia format
          wordnet Enable wordnet plugin to find similar English words using lexical database
          xdxfparse Enable plugin to parse dictionaries in xdxf (XML Dictionary eXchange Format)
          youdaodict Enable youdao.com network plugin (for Chinese language)

          sword

          clucene Use dev-cpp/clucene for lucene search support

          tessdata_best

          osd Enable support orientation and script detection.

          tessdata_fast

          osd Enable support orientation and script detection.

          tessdata_legacy

          math Enable support for recognition of equations.
          osd Enable support orientation and script detection.

          tesseract

          math Enable support for recognition of equations.
          opencl Enable opencl support for speedup using GPU computation.
          osd Enable support orientation and script detection.
          scrollview Install viewer to debug recognition (ScrollView).
          training Install training applications to add support for new languages.

          texlive

          context Add support for the ConTeXt format (dev-texlive/texlive-context)
          detex Add support for dev-tex/detex, a filter program that removes the LaTeX (or TeX) control sequences
          dvi2tty Add support for dev-tex/dvi2tty to preview dvi-files on text-only devices
          epspdf Add support for app-text/epspdf, a tool for converting [e]ps files to pdf
          extra Add support for extra TeXLive packages
          games Add typesetting support for games (chess, etc.) (dev-texlive/texlive-games)
          graphics Add support for several graphics packages (pgf, tikz,...)
          humanities Add LaTeX support for the humanities (dev-texlive/texlive-humanities)
          jadetex Add support for app-text/jadetex (for processing tex files produced by the TeX backend of Jade)
          luatex Add extra support for luatex
          metapost Add support for metapost: A tool for creating graphics in scalable PostScript
          music Add support for music typesetting (dev-texlive/texlive-music)
          pdfannotextractor Add dev-tex/pdfannotextractor support, for extracting annotations from PDF files
          pstricks Add pstricks packages (dev-texlive/texlive-pstricks)
          publishers Add support for publishers (dev-texlive/texlive-publishers)
          science Add typesetting support for natural and computer sciences (dev-texlive/texlive-mathscience)
          tex4ht Add support for dev-tex/tex4ht (for converting (La)TeX to (X)HTML, XML and OO.org)
          texi2html Add support for app-text/texi2html which converts texi files to HTML
          xetex Add support for XeTeX macros (dev-texlive/texlive-xetex)
          xindy 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          texlive-core

          luajittex Add support for LuaJitTeX: LuaTeX based on LuaJIT which is usually faster.
          xetex Add support for XeTeX: a TeX system with Unicode and modern font technologies.

          wdiff

          experimental Build experimental utilities (mdiff, unify, wdiff2)

          webgen

          builder Enable programmatic HTML/XML generation
          highlight Enable syntax highlighting for certain plugins
          markdown Markdown support

          writerperfect

          abiword Add support for abiword format using app-text/libabw
          ebook Add support for various ebook formats using app-text/libebook
          epub Add support for conversion to ePub format using app-text/libepubgen
          freehand Add support for freehand format using media-libs/libfreehand
          gsf Add support for structured files using gnome-extra/libgsf
          keynote Add support for keynote format using app-text/libetonyek
          mspub Add support to mspub format using app-text/libmspub
          mwaw Add support to mwaw formats using app-text/libmwaw
          pagemaker Add support to pagemaker formats using media-libs/libpagemaker
          qxp Add support for QuarkXpress documents using app-text/libqxp
          visio Add support for visio format using media-libs/libvisio
          wpd Add support for wpd format using app-text/libwpd
          wpg Add support for wpg format using app-text/libwpg
          wps Add support for wps format using app-text/libwps
          zmf Add support for Zoner Callisto/Draw documents format using media-libs/libzmf

          wv

          tools Install optional utilities considered deprecated in favor of using AbiWord.

          xmlto

          text Support conversion from XML to plain text

          xpdf

          cmyk Include support for CMYK rasterization
          i18n Enable support non-UTF8 national charsets
          libpaper Use app-text/libpaper to get paper preferences
          metric Use A4 instead of US Letter paper size by default for PostScript output. This option has effect only if libpaper USE flag is disabled
          opi Include support for OPI (Open Prepress Interface) comments
          textselect Allow text selection
          utils Install command-line PDF converters and various utilities

          zathura

          synctex Use libsynctex to get latex codeline from pdf

          zathura-meta

          cb Install plug-in for ComicBook support

          app-vim

          gentoo-syntax

          ignore-glep31 Remove GLEP 31 (UTF-8 file encodings) settings

          youcompleteme

          clang Enable semantic support for C-family languages using sys-devel/clang

          app-xemacs

          xemacs-packages-all

          mule Add multi-language support to XEmacs

          dev-ada

          gnat_util

          shared Build gnat_util shared library
          static-pic Build gnat_util static library with pic code

          gnatcoll-bindings

          shared Build shared library
          static-pic Build shared library

          gnatcoll-core

          shared Build shared library
          static-pic Build static library with pic code

          gnatcoll-db

          db2ada Build gnatcoll_db2ada
          gnatinspect Build gnatinspect
          shared Build shared library
          sql Build sql library
          static-pic Build shared library
          xref Build xref library

          gtkada

          shared Build gtkada as shared library

          libadalang

          shared Build shared library

          libgpr

          shared Build shared library
          static-pic Build static library with pic code

          xmlada

          shared Build shared library
          static-pic Build static library with pic code

          dev-cpp

          eigen

          c++11 Build using the C++11 standard
          cuda Build with cuda support

          glog

          gflags Use dev-cpp/gflags for flag parsing
          unwind Use sys-libs/libunwind for stack unwinding instead of glibc/gcc (may be more reliable on x86_64)

          libcmis

          man Build and install man pages
          tools Build client tool for testing and viewing features

          libjson-rpc-cpp

          http-client Build support for HTTP client using net-misc/curl
          http-server Build support for HTTP server using net-libs/libmicrohttpd
          redis-client Build support for Redis client using dev-libs/hiredis
          redis-server Build support for Redis server using dev-libs/hiredis
          stubgen Build header stub code generator (needed for development and when pregenerated headers are not bundled)

          sourcetrail

          examples Install example projects.

          dev-db

          aerospike-server-community

          tools Install extra tools

          clickhouse

          client Build CLI client.
          kafka Enables support for kafka consumer.
          mongodb Enabled support for MongoDB-based dictionaries
          server Build server.
          tools Build various tools, like benchmark, copier, etc.
          zookeeper Enable support for clustering (based on Zookeeper).

          etcd

          server Installs etcd daemon

          firebird

          server Install the server components of Firebird, not just the client
          xinetd Install ClassicServer

          mariadb

          backup Build mariadb-backup which supports SST and hot backup of InnoDB, Aria and MyISAM including compression and encryption
          client-libs Build the client libraries from the server package instead of the C Connector packages
          extraengine Add support for alternative storage engines (Archive, CSV, Blackhole, Federated(X), Partition)
          galera Enables galera replication
          innodb-lz4 Enables lz4 compression methods for InnoDB/XtraDB
          innodb-lzo Enables lzo compression methods for InnoDB/XtraDB
          innodb-snappy Enables snappy compression methods for InnoDB/XtraDB using app-arch/snappy
          jdbc Enable the CONNECT engine to access foreign databases via JDBC
          latin1 Use LATIN1 encoding instead of UTF8
          libressl Enable SSL connections and crypto functions using dev-libs/libressl
          mroonga Add support for the Mroonga engine for interfacing with the Groonga text search
          numa Enable NUMA support using sys-process/numactl (NUMA kernel support is also required)
          oqgraph Add support for the Open Query GRAPH engine
          pam Enable the optional PAM authentication plugin for the server
          profiling Add support for statement profiling (requires USE=community).
          rocksdb Add support for RocksDB; a key/value, LSM database optimized for flash storage
          server Build the server program
          sphinx Add suport for the sphinx full-text search engine
          sst-mariabackup Add tools needed to support the mariabackup SST method
          sst-rsync Add tools needed to support the rsync SST method
          sst-xtrabackup Add tools needed to support the xtrabackup and xtrabackup-v2 SST methods
          systemtap Build support for profiling and tracing using dev-util/systemtap
          test Install upstream testsuites for end use.
          tokudb Add support for TokuDB storage engine
          yassl Enable SSL connections and crypto functions using the bundled yaSSL

          mariadb-connector-c

          mysqlcompat Enable mysqlclient library symbolic links

          mongodb

          lto Adds support for link time optimization
          mms-agent Install the MongoDB Monitoring Service agent
          tools Install the MongoDB tools (mongoimport, mongodump...) from app-admin/mongo-tools

          mycli

          ssh Add support for connection over SSH tunnel

          mysql

          cjk Add CJK support for InnoDB fulltext search using app-text/mecab
          client-libs Build the client libraries from the server package instead of the C Connector packages (not recommended)
          experimental Build experimental features aka "rapid" plugins
          latin1 Use LATIN1 encoding instead of UTF8
          libressl Enable SSL connections and crypto functions using dev-libs/libressl
          numa Enable NUMA support using sys-process/numactl (NUMA kernel support is also required)
          profiling Add support for statement profiling (requires USE=community).
          router Build the MySQL router program
          server Build the server program
          systemtap Build support for profiling and tracing using dev-util/systemtap
          test Install upstream testsuites for end use.
          yassl Enable SSL connections and crypto functions using the bundled yaSSL

          mysql-cluster

          client-libs Build the client libraries from the server package instead of the C Connector packages (not recommended)
          extraengine Add support for alternative storage engines (Archive, CSV, Blackhole, Federated(X), Partition)
          latin1 Use LATIN1 encoding instead of UTF8
          libressl Enable SSL connections and crypto functions using dev-libs/libressl
          numa Enable NUMA support using sys-process/numactl (NUMA kernel support is also required)
          profiling Add support for statement profiling (requires USE=community).
          server Build the server program
          systemtap Build support for profiling and tracing using dev-util/systemtap
          test Install upstream testsuites for end use.
          yassl Enable SSL connections and crypto functions using the bundled yaSSL

          mysql-connector-c++

          gcov Build coverage support
          legacy Build the legacy 1.x API as well as the DevX API

          opendbx

          man Build and install man pages

          oracle-instantclient

          jdbc Support for XA, Internationalization, and RowSet operations under JDBC
          odbc Libraries for enabling ODBC applications
          precomp "proc" binary and related files to precompile a Pro*C application
          sdk Header files and an example makefile for developing Oracle applications
          sqlplus The SQL*Plus command line tool for SQL and PL/SQL queries
          tools Data Pump, SQL*Loader and Workload Replay Client

          percona-server

          cjk Add CJK support for InnoDB fulltext search using app-text/mecab
          client-libs Build the libmysqlclient libraries
          experimental Build experimental features aka "rapid" plugins
          latin1 Use LATIN1 encoding instead of UTF8
          libressl Enable SSL connections and crypto functions using dev-libs/libressl
          numa Enable NUMA support using sys-process/numactl (NUMA kernel support is also required)
          profiling Add support for statement profiling (requires USE=community).
          rocksdb Add support for RocksDB; a key/value, LSM database optimized for flash storage
          router Build the MySQL router program
          server Build the server program
          systemtap Build support for profiling and tracing using dev-util/systemtap
          tokudb Add support for TokuDB storage engine
          tokudb-backup-plugin Builds the TokuDB backup plugin
          yassl Enable SSL connections and crypto functions using the bundled yaSSL

          pgbouncer

          c-ares Use c-ares as the DNS backend instead of evdns (libevent).
          udns Use udns as the DNS backend instead of evdns (libevent). Supports IPv4 only.

          pgpool2

          memcached Use memcached for query caching.

          pgrouting

          html Install HTML formatted documentation

          phpmyadmin

          setup Installs the phpMyAdmin setup utility. Users who don't use the utility should disable this USE flag for security reasons as the setup tool was the target of various exploits in the past.

          postgis

          address-standardizer Normalize US and CA postal addresses
          gtk Build graphical interface for shp2pgsql (shp2pgsql-gui)
          mapbox Add capability to transform geometry into Mapbox Vector Tile
          topology Build topology spatial types and functions

          postgresql

          llvm Add support for llvm JIT engine
          pg_legacytimestamp Use double precision floating-point numbers instead of 64-bit integers for timestamp storage.
          server Disable to build and install the clients and libraries only.
          uuid Enable server side UUID generation (via dev-libs/ossp-uuid).

          psqlodbc

          iodbc Use dev-db/libiodbc. Disable to use dev-db/unixODBC.

          redis

          tcmalloc Use tcmalloc from dev-util/google-perftools for allocations.

          spatialite

          geos Add the sci-libs/geos library for exact topological tests
          proj Add the sci-libs/proj library for reprojection features
          xls Add the dev-libs/freexl library for xls import support

          sqldeveloper

          sybase Add support for the Sybase SQL Database Server

          sqlite

          secure-delete Enable overwriting of deleted content with zeros by default (//sqlite.org/pragma.html#pragma_secure_delete), causing some performance penalty
          tools Install additional tools

          sqlitestudio

          cli Build CLI interface

          tokumx

          pax_kernel Apply patch needed for hardened kernels

          unixODBC

          minimal Disable bundled drivers and extra libraries (most users don't need these)
          odbcmanual Administrator, Internal Structure, Programmer and User documentation

          dev-embedded

          avrdude

          ftdi Enable support for USB FTDI chips via dev-embedded/libftdi

          libftdi

          tools build ftdi_eeprom helper tool

          openocd

          cmsis-dap Support for CMSIS-DAP compliant adapters
          dummy Build the dummy port driver
          ftdi Enable support for USB FTDI chips via dev-embedded/libftdi
          jlink Build the SEGGER J-Link driver
          parport Enable support for parport JTAG devices
          verbose-io Verbose IO and comm JTAG and USB messages

          sdcc

          avr Add support for AVR -- not supported upstream
          boehm-gc Enable Hans Boehm's garbage collector dev-libs/boehm-gc
          device-lib Enable built of devices libraries
          ds390 Add support for Dallas DS390
          ds400 Add support for Dallas DS400
          gbz80 Add support for Gameboy gbz80
          hc08 Add support for Freescale/Motorola HC08 based
          mcs51 Add support for Intel mcs51
          non-free Enable non-free runtime library parts
          packihx Enable Intel HEX files pack utility
          pic14 Add support for Microchip 14 bits PICs
          pic16 Add support for Microchip 16 bits PICs
          r2k Add support for Rabbit 2000
          r3ka Add support for Rabbit 3000A
          s08 Add support for Freescale/Motorola S08
          sdbinutils Enable SDCC library archive utilities sdar, sdranlib, sdnm
          sdcdb Enable SDCC source level debugger
          sdcpp Enable SDCC preprocessor based on GCC cpp
          stm8 Add support for STMicroelectronics STM8
          tlcs90 Add support for TLCS-90
          ucsim 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          z180 Add support for Zilog Z180
          z80 Add support for Zilog Z80

          urjtag

          ftd2xx Enable support for USB FTDI chips via dev-embedded/libftd2xx
          ftdi Enable support for USB FTDI chips via dev-embedded/libftdi

          dev-games

          aseprite

          bundled-libs Use the upstream provided bundled version of allegro 4.4.2
          gtk3 Enable support for the experimental native GTK File Dialog

          cegui

          devil Build the DevIL based ImageCodec module
          freeimage Build the FreeImage based ImageCodec module
          irrlicht Enable the Irrlicht renderer
          ogre Enable the OGRE renderer
          tinyxml 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          xerces-c Enable the Xerces-C++ XML parser module
          zip Enable the Minizip resource provider

          guichan

          allegro Build the Allegro frontend

          mygui

          l10n_ru Install some additional russian docs if 'doc' useflag enabled
          ogre Use the ogre render subsystem. (cannot combine with opengl)
          opengl Use the opengl render subsystem. (cannot combine with ogre)
          plugins Build MyGUI plugins
          samples Install MyGUI demos (needs ogre USE flag)
          tools Build the tools for development

          ode

          double-precision more precise calculations at the expense of speed
          gyroscopic enable gyroscopic term (may cause instability)

          ogre

          boost Enable boost support
          cache Enable GL state cache support
          cg NVIDIA toolkit plugin
          double-precision More precise calculations at the expense of speed
          egl Use egl instead of glx
          experimental Build experimental BETA component 'HLMS'
          freeimage Support images via media-libs/freeimage
          gl3plus Build OpenGL 3+ RenderSystem (EXPERIMENTAL)
          gles2 Build OpenGL ES 2.x RenderSystem
          gles3 Enable OpenGL ES 3.x Features
          json Use dev-libs/rapidjson (needed by Hlms JSON materials)
          legacy-animations Use the skeletal animation from 1.x. It's much slower, but the new system is still experimental.
          mobile Build for OpenGL ES 2.0 only and use the mobile variants of the PBS and unlit material systems.
          ois Pull in Object-oriented Input System library dev-games/ois for samples
          poco When USE=threads, use poco for threading
          resman-pedantic Resource Manager PEDANTIC : require an explicit resource group. Case sensitive lookup. Some demos might not work with this setting. (default: case-insensitive + sensitive lookup in all groups)
          resman-strict Resource Manager STRICT : search in default group if not specified otherwise. Case sensitive lookup. Some demos might not work with this setting. (default: case-insensitive + sensitive lookup in all groups)
          tbb When USE=threads, use tbb for threading
          tools Build and install helper tools

          openscenegraph

          asio Enable support for dev-cpp/asio library
          dicom Enable DICOM medical image file support via sci-libs/dcmtk
          egl Enable EGL support
          fox Build examples using x11-libs/fox library
          gdal Enable support for sci-libs/gdal library
          las Enable support for geospatial data LAS LiDAR format using sci-geosciences/liblas
          openinventor Build OpenInventor plugin
          osgapps Build osg applications
          sdl2 Use media-libs/libsdl2 additionally to media-libs/libsdl
          xrandr Enable support for the X xrandr extension

          physfs

          7zip Enable 7zip/lzma archive support
          grp Enable Build Engine GRP archive support
          hog Enable Descent I/II HOG archive support
          iso Enable ISO9660 file support
          mvl Enable Descent I/II MVL archive support
          qpak Enable Quake I/II QPAK archive support
          slb Enable Independence War SLB archive support
          vdf Enable Gothic/Gothic II VDF archive support
          wad Enable Doom WAD archive support

          simgear

          dns Enable DNS resolver via net-libs/udns
          gdal Enable alternative terrain engine based on pagedLOD via sci-libs/gdal
          subversion Enable terrasync scenery downloader

          dev-haskell

          abstract-deque

          usecas Enable the reference implementation to use hardware compare-and-swap.

          aeson-pretty

          lib-only don't build 'aeson-pretty' executable.

          ansi-terminal

          example Build the example application.

          ansi-wl-pprint

          example Build the example application.

          authenticate

          network-uri Get Network.URI from the network-uri package

          bifunctors

          semigroups You can disable the use of the `semigroups` package using `-f-semigroups`. Disabing this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.
          tagged You can disable the use of the `tagged` package using `-f-tagged`. Disabing this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.

          biosff

          fclip Build the fclip executable.
          flower Build the flower executable.
          frecover Build the frecover executable.

          blaze-builder-enumerator

          newbuilder use bytestring-builder instead of blaze-builder-0.3

          bytedump

          executable build executable file

          bytes

          test-doctests Enable the doctest suite when using the enable-tests option for cabal.

          c2hs

          regression run regression tests

          cabal-install

          network-uri Get Network.URI from the network-uri package.
          noprefs Ignore 'preferred-versions' file from hackage's tarball.

          certificate

          executable Build the executable

          cgi

          extensible-exceptions-in-base Required to be enabled for >=dev-lang/ghc-7.
          network-uri Get Network.URI from the network-uri package.

          chell

          color-output use colors in program output

          citeproc-hs

          bibutils 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          embed-data-files Embed locale files into the library (needed for windows packaging)
          hexpat use dev-haskell/hexpat instead of dev-haskell/xml for XML parsing
          network use dev-haskell/network and dev-haskell/http to retrieve CSL file from URIs
          small-base Choose the new smaller, split-up base package.
          unicode-collation Use Haskell bindings to the dev-libs/icu

          cmark

          system-cmark use app-text/cmark instead of bundled copy

          cmdargs

          quotation Build quote module
          testprog Build the test program

          comonad

          containers You can disable the use of the `containers` package using `-f-containers`. Disabing this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.
          contravariant You can disable the use of the `contravariant` package using `-f-contravariant`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. If disabled we will not supply instances of `Contravariant`
          distributive You can disable the use of the `distributive` package using `-f-distributive`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. If disabled we will not supply instances of `Distributive`
          test-doctests Run the doctests test suite

          conduit

          nohandles experimental code to use raw system calls in place of handles. Not recommended for general use

          configfile

          buildtests Build the executable to run unit tests.

          contravariant

          safe Get Safe guarantees rather than merely Trustworthy, but with worse constant factors.
          semigroups You can disable the use of the `semigroups` package using `-f-semigroups`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.
          statevar You can disable the use of the `StateVar` package using `-f-StateVar`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.
          tagged You can disable the use of the `tagged` package on older versons of GHC using `-f-tagged`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.

          cpu

          executable build 'cpuid' tool

          crypto-api

          all-cpolys Build all the CMAC polynomes up to 10000 bits instead of just the usual ones

          crypto-conduit

          conduit11 Use conduit >= 1.1.

          cryptohash

          cryptoapi Defines crypto-api instances

          cryptonite

          cpu-flags-x86-rdrand allow compilation with RDRAND on system and architecture that supports it
          integer-gmp Whether or not to use GMP for some functions

          dav

          network-uri Get Network.URI from the network-uri package.

          distributive

          lib-werror Compile with the ghc -Werror option

          encoding

          systemencoding Provide the getSystemEncoding action to query the locale.

          entropy

          halvm Build for the HaLVM.

          filestore

          maxcount Make use of a recent (>= 2.3.0) Darcs feature which vastly improves the performance of 'latest'. You should disable this flag if you plan to use gitit with an older version of Darcs, or 'latest' will raise an error.

          glib

          closure-signals Use the the GClosure-based signals implementation.

          gtk

          deprecated Include definitions in this library that are considered obsolete.
          fmode-binary Set the default file translation mode for file I/O operations to _O_BINARY.
          gio Depend on GIO package, thereby enabling certain features.

          gtk2hs-buildtools

          closuresignals Use the the GClosure-based signals implementation.

          gtk3

          fmode-binary Set the default file translation mode for file I/O operations to _O_BINARY.
          gio Depend on GIO package, thereby enabling certain features.

          hackage-security

          use-network-uri Get Network.URI from the network-uri package.

          happstack-server

          network-uri Get Network.URI from the network-uri package
          template-haskell Description: Template Haskell is available on this system

          hashed-storage

          diff Provide the Storage.Hashed.Diff module.
          hpc Compile with the profiling ghc flag -fhpc.

          hashtables

          bounds-checking if on, use bounds-checking array accesses
          portable if on, use only pure Haskell code and no GHC extensions.
          unsafe-tricks turn on unsafe GHC tricks

          haskeline

          legacy-encoding Use legacy iconv encoding for POSIX. This is only intended for testing.
          libiconv Explicitly link against the libiconv library.
          terminfo Use the terminfo package for POSIX consoles.

          hdbc-odbc

          buildstresstest Build stress test

          hdbc-sqlite3

          buildtests Build the executable to run unit tests
          splitbase Choose the new smaller, split-up package.

          hexpat

          bundled-expat Use bundled expat instead of dev-libs/expat

          highlighting-kate

          executable Build the Highlight executable.
          pcre-light Use the pcre-light library instead of regex-pcre-builtin.

          hit

          executable Build the executable

          hlint

          gpl Use GPL libraries, specifically hscolour.

          hps

          build-exec Build the `hps-fractals' executable

          hs3

          network-uri Get Network.URI from the network-uri package.

          hslogger

          buildtests Build the executable to run unit tests.

          hslua

          apicheck Compile Lua with -DLUA_USE_APICHECK..
          system-lua Use the system-wide lua instead of the bundled copy.

          hsopenssl

          fast-bignum Enable fast moving of bignums between OpenSSL and GMP (GHC Only)

          http

          conduit10 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          network-uri Get Network.URI from the network-uri package.

          http-api-data

          use-text-show Use text-show library for efficient ToHttpApiData implementations

          http-client

          network-uri Get Network.URI from the network-uri package.

          http-streams

          network-uri Get Network.URI from the network-uri package.

          httpd-shed

          buildexamples Build example executables.
          network-uri Get Network.URI from the network-uri package.

          hxt

          network-uri Get Network.URI from the network-uri package.

          icalendar

          network-uri use network-uri package

          json

          generic Add support for generic encoder (dev-haskell/syb)
          mapdict Encode Haskell maps as JSON dicts
          parsec Add support for parsing with Parsec
          pretty Add support for using pretty printing combinators

          language-dot

          executable Build the `ppdot' executable

          lens

          benchmark-uniplate Enable benchmarking against Neil Mitchell's uniplate library for comparative performance analysis. Defaults to being turned off to avoid the extra dependency.
          dump-splices Build and run the doctests test-suite.
          inlining Generate inline pragmas when using template-haskell. This defaults to enabled, but you can to shut it off to benchmark the relative performance impact, or as last ditch effort to address compile errors resulting from the myriad versions of template-haskell that all purport to be 2.8.
          j Attempt a parallel build with GHC 7.8.
          lib-werror Turn on ghc-options: -Werror
          old-inline-pragmas Some 7.6.1-rc1 users report their TH still uses old style inline pragmas. This lets them turn on inlining.
          safe Disallow unsafeCoerce
          test-doctests Build and run the doctests test-suite.
          test-hlint You can disable the hlint test suite with -f-test-hlint
          test-hunit You can disable the hunit test suite with -f-test-hunit
          test-properties Build the properties test if we're building tests
          test-templates Build the test templates if we're building tests
          trustworthy Assert that we are trustworthy when we can

          lifted-async

          monad-control-1 Use moand-control == 1.*

          linear

          template-haskell You can disable the use of the `template-haskell` package using `-f-template-haskell`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.

          monad-control

          instancest If enabled this package will export MonadBaseControl instances for the lazy and strict ST monad. If disabled these instances are only exported when base >= 4.4. If enabled it is required that the transformer-base package exports MonadBase instances for ST. It will do this by default.

          monad-logger

          template-haskell Enable Template Haskell support.

          monad-par

          chaselev Use Chase-Lev Deques for higher-perf work-stealing.

          nats

          hashable You can disable the use of the `hashable` package using USE=-hashable. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. If set we will not supply an instance of `Hashable`.

          network-data

          small-base Build the split-up base package.

          pandoc-citeproc

          bibutils 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          embed-data-files Embed locale files into the library (needed for windows packaging)
          hexpat use dev-haskell/hexpat instead of dev-haskell/xml for XML parsing
          network use dev-haskell/network and dev-haskell/http to retrieve CSL file from URIs
          small-base Choose the new smaller, split-up base package.
          test-citeproc Build the test-citeproc program
          unicode_collation Use Haskell bindings to the dev-libs/icu

          persistent

          nooverlap Use OverlappingInstances only for String. Only developers should use this.

          persistent-sqlite

          build-sanity-exe Build a sanity check test executable.

          pointed

          comonad optional instances
          containers optional instances
          kan-extensions optional instances
          semigroupoids optional instances
          semigroups optional instances
          stm optional instances
          tagged optional instances
          transformers optional instances
          unordered-containers optional instances

          publicsuffixlist

          create export Network.PublicSuffixList.Create module
          runtimelist 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          quickcheck

          template-haskell Enable additional test modules requiring Template Haskell support.

          recaptcha

          network-uri Get Network.URI from the network-uri package.

          reflection

          template-haskell Enable template haskell.

          rfc5051

          mkunicodedata build codes generator itself

          sandi

          with-conduit Build with conduit

          scientific

          bytestring-builder Provide the Data.ByteString.Builder.Scientific module (requires bytestring >= 0.10).

          semigroupoid-extras

          profunctors You can disable the use of the `profunctors` package using `-f-profunctors`. Disabing this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.

          semigroupoids

          comonad You can disable the use of the `comonad` package using `-f-comonad`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. If disabled we will not supply instances of `Comonad`
          containers You can disable the use of the `containers` package using `-f-containers`. Disabing this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.
          contravariant You can disable the use of the `contravariant` package using `-f-contravariant`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. If disabled we will not supply instances of `Contravariant`
          distributive You can disable the use of the `distributive` package using `-f-distributive`. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. If disabled we will not supply instances of `Distributive`
          tagged You can disable the use of the `tagged` package using `-f-tagged`. Disabing this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.

          semigroups

          binary provide instances for binary package
          bytestring You can disable the use of the `bytestring` package using USE=-bytestring. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.
          containers You can disable the use of the `containers` package using USE=-containers. Disabing this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.
          deepseq You can disable the use of the `deepseq` package using `-f-deepseq`. Disabing this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.
          hashable You can disable the use of the `hashable` package using USE=-hashable. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. If set we will not supply an instance of `Hashable`.
          text You can disable the use of the `text` package using USE=-text. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.
          transformers provide instances for transformers package.
          unordered-containers You can disable the use of the `unordered-containers` package using USE=-unordered-containers. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users.

          sendfile

          portable Explicitly enable portable sendfile support (implemented in Haskell)

          sha

          exe Build a sha1 and a sha384 executable similar to 'md5sum'.

          shakespeare

          test-coffee Render tests through coffeescript render function.
          test-export Test export.
          test-roy Render tests through roy render function.

          shakespeare-js

          test-coffee Test coffee.
          test-export Test export.
          test-roy Test roy.

          shelly

          lifted run the tests against Shelly.Lifted

          shuffle

          network-uri Get Network.URI from the network-uri package.

          simple-sendfile

          allow-bsd Allow use of BSD sendfile (disable on GNU/kFreeBSD)

          skein

          big-endian When manually selecting the endianness, use big-endian (default is little-endian)
          force-endianness Use a manually selected endian when compiling (see flag 'big-endian')
          reference Use the reference implementation instead of the optimized one

          skylighting

          executable Build the skylighting executable.

          snap-core

          portable No non-haskell unportable code.

          snap-server

          build-pong Build a server that just returns "PONG"
          openssl enable https support using dev-haskell/hsopenssl
          portable no non-haskell unportable code.

          tagsoup

          download Build with Download module.
          testprog Build the test program.

          tasty

          colors Enable colorful output

          tasty-quickcheck

          old-quickcheck Use Quick-Check < 2.7.

          texmath

          executable Compile test executable.
          network-uri Get Network.URI from the network-uri package.

          text

          developer operate in developer mode

          thyme

          bug-for-bug bug-for-bug compatibility with time
          lens use the full lens package
          show-internal instance Show of internal representation

          tls

          compat Accept SSLv2 compatible handshake.
          network Use the base network library.

          transformers-base

          orphaninstances Build instances for orphan datatypes.

          transformers-compat

          three Use transformers-0.3

          unix-compat

          old-time build against old-time package

          uuagc

          with-loag Use dev-haskell/minisat external SAT-solver to schedule all Linear Ordered AGs.

          vector

          boundschecks Enable bounds checking
          internalchecks Enable internal consistency checks at the cost of a significant performance penalty
          unsafechecks Enable bounds checking in unsafe operations at the cost of a significant performance penalty

          vector-algorithms

          bench Build a benchmarking program.
          boundschecks Enable bounds checking.
          internalchecks Enable internal consistency checks at the cost of a significant performance penalty.
          properties Enable quickcheck tests.
          unsafechecks Enable bounds checking in unsafe operations at the cost of a significant performance penalty.

          void

          safe dissable effective but unsafe coersions

          wai-app-static

          print print debug info.

          warp

          allow-sendfilefd Allow use of sendfileFd (not available on GNU/kFreeBSD).
          warp-debug Add additional debuging information

          x11

          screensaver whether to build XScreenSaver.

          x509-store

          executable Build the executable

          xss-sanitize

          network-uri Get Network.URI from the network-uri package.

          yaml

          no-examples don't build the examples
          no-exe don't install the yaml2json executable
          no-unicode Don't enable unicode output. Instead, unicode characters will be escaped.
          system-libyaml Use system libyaml instead on generic one

          yesod-auth

          network-uri Get Network.URI from the network-uri package

          yesod-form

          network-uri Get Network.URI from the network-uri package

          zip-archive

          executable Build the Zip executable.

          zlib

          non-blocking-ffi Execute FFI calls in the context of haskell thread.

          dev-java

          ant

          antlr Enable ANTLR Ant tasks
          bcel Enable bcel (bytecode manipulation) Ant tasks
          bsf Enable support for Apache Bean Scripting Framework (dev-java/bsf)
          commonslogging Enable commons-logging Ant tasks
          commonsnet Enable commons-net Ant tasks
          jai Enable JAI (Java Imaging) Ant task
          javamail Enable JavaMail Ant task
          jdepend Enable Jdepend Ant tasks
          jmf Enable JMF (Java Media Framework) Ant tasks
          jsch Disable Jsch (ssh, scp and related) Ant tasks
          junit Enable JUnit Ant tasks
          junit4 Enable JUnit4 Ant tasks
          junitlauncher Enable JUnit5 Ant tasks
          log4j Enable Apache log4j Ant tasks
          oro Enable Apache Oro Ant tasks
          regexp Enable Apache Regexp Ant tasks
          resolver Enable Apache Resolver Ant tasks
          swing Enable Swing Ant tasks
          testutil Enable optional test util classes
          xz Enable XZ Ant tasks

          commons-collections

          test-framework Install the test framework

          commons-logging

          avalon-framework Add optional support for avalon-framework
          avalon-logkit Add optional support for avalon-logkit
          log4j Add optional support for log4j
          servletapi Add optional support for servletapi

          ecj-gcj

          native Build a native binary along with the jar. Provides faster execution time, but needs about 1G memory and some patience to compile.

          eclipse-ecj

          ant Support using ecj in Ant builds via dev-java/ant-eclipse-ecj

          emma

          launcher Install /usr/bin/emma. Collides with sci-biology/emboss.

          gcj-jdk

          awt Install AWT libraries, needed by some GUIs (not needed to build icedtea)

          gnu-classpath

          alsa Build with ALSA javax.sound.midi provider
          dssi Build with DSSI javax.sound.midi provider
          gconf Build with GConf preferences backend
          gjdoc Build GJDoc, a documentation generator
          gmp Build with GMP backend for java.math.BigInteger
          gtk Build with Gtk+ AWT peers
          xml Build with native XML backend

          icedtea

          cacao Use the CACAO virtual machine rather than HotSpot.
          cups Link against the CUPS library at compile time, rather than using it dynamically at runtime.
          headless-awt Don't install the X backend for AWT, needed by some GUIs (used to be X flag)
          jamvm Use the JamVM virtual machine rather than HotSpot.
          jbootstrap If possible, recompile the final IcedTea executables with itself.
          kerberos Link against Kerberos in order to obtain the cache location.
          nsplugin Enable browser plugin (NPPlugin), requires also the webstart flag to be enabled.
          pax_kernel Apply patch needed for pax enabled kernels.
          pch Build using pre-compiled headers.
          sctp Build the SCTP NIO channel implementation against lksctp
          shenandoah Include the Shenandoah ultra-low pause time garbage collector (-XX:+UseShenandoahGC) (arm64 and x86_64 only)
          smartcard Build the PCSC driver against pcsc-lite
          system-lcms Build against the system LCMS installation rather than the in-tree copy.
          webstart Enable Web Start support (via NetX).
          zero Enable Zero assembler port (usually for non-HotSpot architectures)

          icedtea-bin

          headless-awt Don't install the X backend for AWT, needed by some GUIs (used to be X flag)
          webstart Provide javaws command through symlink to icedtea-web

          icedtea-web

          javascript Enable support for using proxy auto config (PAC) files.
          nsplugin Enable the browser plugin (NPPlugin).
          tagsoup Depend on dev-java/tagsoup which allows parsing malformed .jnlp files

          jdbc-mysql

          c3p0 Enable c3p0 support
          log4j Enable log4 support

          jfreesvg

          debug Enable debugging during compilation.

          jna

          awt Enables support for Java AWT
          nio-buffers Enables support for NIO buffers

          log4j

          javamail Build the SMTPAppender
          jms Build the JMSAppender

          lucene

          contrib Include extra functionality from contrib/

          miglayout

          swt Add support for the SWT toolkit.

          openjdk

          gentoo-vm Allow this JDK to be recognised by 沙巴体育 (package manager, eselect, java-config, EXPERIMENTAL!)
          headless-awt Don't install the X backend for AWT, needed by some GUIs
          javafx Import OpenJFX modules at build time, via dev-java/openjfx
          jbootstrap Build OpenJDK twice, the second time using the result of the first
          source Install JVM sources
          systemtap Enable SystemTAP/DTrace tracing
          webstart Provide javaws command through symlink to icedtea-web

          openjdk-bin

          gentoo-vm Allow this JDK to be recognised by 沙巴体育 (package manager, eselect, java-config, EXPERIMENTAL!)
          headless-awt Don't install the X backend for AWT, needed by some GUIs (used to be X flag)
          source Install JVM sources
          webstart Provide javaws command through symlink to icedtea-web

          openjdk-jre-bin

          gentoo-vm Allow this JDK to be recognised by 沙巴体育 (package manager, eselect, java-config, EXPERIMENTAL!)
          headless-awt Don't install the X backend for AWT, needed by some GUIs (used to be X flag)
          webstart Provide javaws command through symlink to icedtea-web

          openjfx

          media Compile media module, based on gstreamer-minimal (does not pull gstreamer)
          source Install JavaFX sources

          oracle-jdk-bin

          commercial Install features requiring a commercial license for production use
          gentoo-vm Allow this JDK to be recognised by 沙巴体育 (package manager, eselect, java-config, EXPERIMENTAL!)
          gtk2 Enable GTK+ 2 support in JavaFX
          gtk3 Enable GTK+ 3 support in JavaFX
          headless-awt Don't install the X backend for AWT, needed by some GUIs (used to be X flag)
          javafx Install JavaFX libraries
          jce Install Java Cryptographic Extension Unlimited Strength Jurisdiction Policy Files
          source Install JVM (and optionally JavaFX) sources
          visualvm Install VisualVM debugging tool

          oracle-jre-bin

          commercial Install features requiring a commercial license for production use
          headless-awt Don't install the X backend for AWT, needed by some GUIs (used to be X flag)
          javafx Install JavaFX libraries
          jce Install Java Cryptographic Extension Unlimited Strength Jurisdiction Policy Files

          rxtx

          lfd Installs and uses LockFileServer daemon (lfd)

          sbt

          binary Install from (沙巴体育-compiled) binary instead of building from sources. Set this when you run out of memory during build.

          dev-lang

          bas

          lr0 Use the LR0 parser instead of the recursive descending parser

          crystal

          blocking-stdio-hack Keep STDIO file descriptors in blocking mode.
          debug Build each module as a separate object file. Speeds build up.
          xml Use the dev-libs/libxml2 library to enable Crystal xml module
          yaml Use the dev-libs/libyaml library to enable Crystal yaml module

          erlang

          hipe HIgh Performance Erlang extension
          kpoll Enable kernel polling support
          pgo Build erts with profile-guided optimizations

          fpc

          ide Build and install the Free Pascal Compiler IDE

          gdl

          eigen Build matrix manipulation with dev-cpp/eigen
          gshhs Add support for projection adn continent maps with sci-geosciences/gshhs-data
          hdf Add support for the Hierarchical Data Format v.4
          proj Add support for sci-libs/proj (geographic projections)
          udunits Add support for manipulating units of physical quantities

          ghc

          binary Install the binary version directly, rather than using it to build the source version.
          elfutils Enable DWARF-based baclktraces using dev-libs/elfutils.
          ghcbootstrap Internal: Bootstrap GHC from an existing GHC installation.
          ghcmakebinary Internal: Build binary friendly for redistribution.
          gmp use dev-libs/gmp for integer operations (works faster, but an external depend).
          numa Enable NUMA thread balancing policy using sys-process/numactl.

          gnat-gpl

          awt 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          bootstrap Used to bootstrap gnat-gpl
          cilk Support the Cilk Plus language (C/C++ based languages for parallel programming)
          fixed-point Enable fixed-point arithmetic support for MIPS targets in gcc (Warning: significantly increases compile time!)
          gcj Build the GCJ Java language frontend.
          go Build the GCC Go language frontend.
          graphite Add support for the framework for loop optimizations based on a polyhedral intermediate representation
          libssp Build SSP support into a dedicated library rather than use the code in the C library (DO NOT ENABLE THIS IF YOU DON'T KNOW WHAT IT DOES)
          mpx Enable support for Intel Memory Protection Extensions (MPX)
          nopie Disable PIE support (NOT FOR GENERAL USE)
          nossp Disable SSP support (NOT FOR GENERAL USE)
          nptl Enable support for Native POSIX Threads Library, the new threading module (requires linux-2.6 or better usually)
          objc Build support for the Objective C code language
          objc++ Build support for the Objective C++ language
          objc-gc Build support for the Objective C code language Garbage Collector
          pgo Build GCC using Profile Guided Optimization (PGO)
          sanitize Build support for various sanitizer functions (ASAN/TSAN/etc...)
          ssp Build packages with stack smashing protector on by default
          systemtap enable systemtap static probe points
          vtv Build support for virtual table verification (a C++ hardening feature)

          go

          gccgo Bootstrap using sys-devel/gcc[go]
          system-bootstrap Bootstrap using previously installed dev-lang/go

          icon

          iplsrc install the icon programming library source

          jsonnet

          custom-optimization Build with user-specified compiler optimizations (-Os, -O0, -O1, -O2, -O3) from CFLAGS (unsupported)

          lazarus

          minimal Don't build extra packages from the bigide component

          logtalk

          fop Support for generating pdf documentation using fop
          xslt Support for generating html documentation using xslt

          lua

          deprecated make deprecated data structures/routines available
          test-complete Run the complete (non-portable) testsuite

          luajit

          lua52compat Enable some upwards-compatible features from Lua 5.2 that are unlikely to break existing code.

          mercury

          erlang Support Mercury Erlang grade
          trail Support Mercury trail grades

          mlton

          binary install a binary version
          bootstrap-smlnj Boostrap mlton with dev-lang/smlnj (takes a long time)
          pax_kernel Enable if the user plans to run the package under a pax enabled hardened kernel
          stage3 After bootstrap building mlton with dev-lang/smlnj, rebuild mlton with the second stage build of mlton (recommended).

          moarvm

          asan Enable clang's Address Sanitizer functionality. Expect longer compile time.
          clang Use clang compiler instead of GCC
          jit Enable Just-In-Time-Compiler. Has no effect except on AMD64 and Darwin.
          optimize Enable optimization via CFLAGS
          ubsan Enable clang's Undefined Behavior Sanitizer functionality. Expect longer compile time.

          mono

          pax_kernel Enable if the user plans to run the package under a pax enabled hardened kernel
          xen Make mono generate code that is considerably faster on xen VMs but slightly slower on for normal systems.

          nqp

          clang Toggle usage of the clang compiler in conjunction with MoarVM
          moar Build the MoarVM backend (experimental/broken)

          ocaml

          flambda Enables the Flambda optimizer: A new intermediate representation (introduced in ocaml 4.03) in the depths of the compiler designed to allow for better inlining.
          spacetime Enables the Spacetime memory profiler. See //caml.inria.fr/pub/docs/manual-ocaml/spacetime.html for more information.

          orc

          pax_kernel Apply patch needed for pax enabled kernels.

          perl

          ithreads Enable Perl threads, has some compatibility problems

          php

          argon2 Enable password hashing algorithm from app-crypt/argon2
          bcmath Add support for libbcmath
          cli Enable CLI SAPI
          coverage Include gcov symbols for test coverage and lcov reports. Only useful for extension developers, and requires GCC.
          ctype Enable ctype functions
          embed Enable embed SAPI
          enchant Add supports Enchant spelling library.
          ffi Add foreign function interface (ffi extension) support
          fileinfo Add fileinfo extension support
          filter Add filter extension support
          flatfile Add dbm support for flat files
          fpm Enable the FastCGI Process Manager SAPI
          gd Adds support for gd (bundled with PHP)
          hash Enable the hash extension
          inifile Add dbm support for .ini files
          intl Enables the intl extension for extended internalization support
          json Enable JSON support
          ldap-sasl Add SASL support for the PHP LDAP extension
          libmysqlclient Use libmyslclient driver for mysql, mysqli, PDO_Mysql (not recommended)
          lmdb Enable support for dev-db/lmdb db backend
          opcache Enables built-in opcode cache, replacing pecl-apc et al.
          pcntl Add support for process creation functions
          pdo Enable the bundled PDO extensions
          phar Enables the phar extension to provide phar archive support
          phpdbg Enable the PHP Debug Command Line SAPI (like gdb for php)
          session-mm Include dev-libs/mm support for session storage
          sharedmem Add support for shared memory use
          simplexml Support for SimpleXML
          sodium Enable support for crypto through dev-libs/libsodium
          sybase-ct Add support for Sybase-CT
          sysvipc Support for System V-compatible inter-process communication
          tokenizer Add support for the PHP file parser
          tokyocabinet Enable support for dev-db/tokyocabinet db backend
          vpx Enable webp support for GD in php-5.x
          wddx Add support for Web Distributed Data eXchange
          webp Enable webp support for GD in php-7.x
          xmlreader Enable XMLReader support
          xmlwriter Enable XMLWriter support
          xslt Enable the XSL extension
          zip-encryption Enable ZIP file encryption from dev-libs/libzip

          polyml

          portable Build the portable interpreter version of Poly/ML instead of native

          python

          bluetooth Build Bluetooth protocol support in socket module
          threads Enable threading support. (DON'T DISABLE THIS UNLESS YOU KNOW WHAT YOU'RE DOING)
          wide-unicode Enable wide Unicode implementation which uses 4-byte Unicode characters. Switching of this USE flag changes ABI of Python and requires reinstallation of many Python modules. (DON'T DISABLE THIS UNLESS YOU KNOW WHAT YOU'RE DOING)
          wininst Install Windows executables required to create an executable installer for MS Windows.

          qu-prolog

          pedro Pedro subscription/notification communications system

          rakudo

          clang Use Clang to compile the MoarVM backend
          moar Use the MoarVM as backend

          ruby

          rdoc Install dev-ruby/rdoc after installing Ruby.
          rubytests Install ruby tests that can only be run after ruby is installed

          rust

          clippy Install clippy component
          rls Install rls component
          rustfmt Install rustfmt component
          system-llvm Use the system LLVM install
          wasm Build support for the wasm32-unknown-unknown target

          rust-bin

          clippy Install clippy component
          rustfmt Install rustfmt component

          scala

          binary Install from (沙巴体育-compiled) binary instead of building from sources. Set this when you run out of memory during build.

          smlnj

          pax_kernel Enable if the user plans to run the package under a pax enabled hardened kernel

          spidermonkey

          custom-optimization Build with user-specified compiler optimizations (-Os, -O0, -O1, -O2, -O3) from CFLAGS (unsupported)
          debug Enable assertions to allow for easier debugging of programs that link to spidermonkey -- note this will often crash software on regular end-user systems
          system-icu Use the system-wide dev-libs/icu instead of bundled -- note, only takes effect when icu flag is enabled
          threadsafe Build a threadsafe version of spidermonkey

          swi-prolog

          archive Use libarchive for extension packs
          uuid Use ossp-uuid for UUID pack
          yaml Use libyaml for YAML pack

          swig

          ccache build ccache-swig(a fast compiler cache)

          vala

          valadoc Installs valadoc documentation generation tool

          yap

          R Enable support for connecting R to Prolog

          zig

          experimental Enable builds that do not support all of LLVM's target architectures

          dev-libs

          antlr-c

          debugger Compiles debug info into the library

          appstream

          apt Enables Debians APT support

          appstream-glib

          fonts Enable fonts support for appstream-builder.
          stemmer Add word stemming via dev-libs/snowball-stemmer.

          apr

          older-kernels-compatibility Enable binary compatibility with older kernels
          urandom Use /dev/urandom instead of /dev/random

          apr-util

          libressl Use dev-libs/libressl instead of dev-libs/openssl for 'openssl' USE flag
          nss Install apr_crypto_nss module
          openssl Install apr_crypto_openssl module

          atcore

          gui Build test GUI

          aws-sdk-cpp

          access-management AWS Access Management, a meta-flag that enables: AWS Certificate Manager (ACM): Provision, manage, and deploy SSL/TLS certificates on AWS managed resources. Identity and Access Management (IAM): A web service for securely controlling access to AWS services. Resource Access Manager (RAM): Customers who operate multiple accounts can create resources centrally and use AWS RAM to share them with all of their accounts to reduce operational overhead. Also enables acm-pca, identity-management and sts (Security Token Service).
          apigateway Create and deploy your own REST and WebSocket APIs at any scale. Also enables apigatewaymanagementapi and apigatewayv2.
          backup AWS Backup is a fully managed backup service
          batch Run batch computing workloads on the AWS Cloud
          budgets Use AWS Budgets to plan service usage, service costs, and instance reservations. Also enables the following related modules: AWS Cost Explorer (CE) : Programmatically query cost and usage data. Cost and Usage Report (CUR): Programmatically create, query, and delete AWS Cost and Usage report definitions.
          chime Amazon Chime, a secure, real-time, unified communications service.
          cloud-desktop AWS end user computing services. AppStream 2.0: Fully managed, secure application streaming service. WorkDocs : Fully managed, secure enterprise storage and sharing service. WorkLink : Fully managed, cloud-based service that enables secure, one-click access to internal websites and web apps from mobile devices. WorkMail : Managed email and calendaring service. WorkSpaces : Cloud-based desktop experience for end users.
          cloud-dev Enables in-cloud developer tools: Cloud9 : Cloud-based integrated development environment IDE to write, run, and debug code. CodeBuild : Managed build service that compiles, runs unit tests and produces artifacts. CodeCommit : Privately store and manage Git repositories in the AWS cloud. CodeDeploy : Automate the deployment and updating of applications. CodePipeline: Continuous delivery service to model, visualize, and automate the steps required to release software. CodeStar : Quickly develop, build, and deploy applications on AWS. Queues : Simple queue class. Allows standard queue operations top, delete, and push. Also has higher level, asynchronous interface with callbacks. X-Ray : Provides request tracing, exception collection, and profiling capabilities.
          cloud-media AWS Media modules for transforming, converting, delivering and streaming media. Elastic Transcoder : Convert media files stored in Amazon S3 into media files in the formats required by consumer playback devices. Elemental Media Connect: Secure and flexible transport service for live video. Elemental Media Convert: Format and compress offline video content for delivery to televisions or connected devices. Elemental Media Live : Video service that allows easy and reliable creation of live outputs for broadcast and streaming delivery. Elemental Media Package: Just-in-time video packaging and origination service. (Includes mediapackage-vod) Elemental Media Store : Video origination and storage service.Manage video assets as objects in containers to build dependable, cloud-based media workflows. (Includes mediastore-data) Elemental Media Tailor : Personalization and monetization service that allows scalable server- side ad insertion.
          cloud-mobile AWS Mobile modules for handling mobile application management and delivery. Amplify : Comprehensive set of SDKs, libraries, tools, and documentation for client app development. AppSync : Enterprise level, fully managed GraphQL service with real-time data synchronization and offline programming features. Device Farm: Test iOS, Android and Fire OS apps on real, physical phones and tablets that are hosted by AWS. PinPoint : Engage customers by sending them email, SMS and voice messages, and push notifications. (Includes pinpoint-email and sms-voice) SNS : Amazon Simple Notification Service, see USE flag sns. Also enables mobile and mobileanalytics.
          cloudformation Create and provision AWS infrastructure deployments predictably and repeatedly. Use a template file to create and delete a collection of resources together as a single unit (a stack).
          cloudfront Delivers static and dynamic web content through a worldwide network of edge locations that provide low latency and high performance.
          cloudhsm Secure cryptographic key storage by providing managed hardware security modules in the AWS Cloud. Also enables cloudhsmv2.
          cloudsearch Fully managed service in the cloud to set up, manage, and scale a search solution for websites. Also enables cloudsearchdomain.
          cloudwatch 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          cognito Create unique identities, authenticate these identities with identity providers and save mobile user data in the AWS Cloud. Enables cognito-identity, cognito-idp and cognito-sync
          config Provides a detailed view of the resources associated with your AWS account, including how they are configured, how they are related to one another, and how the configurations and their relationships have changed over time.
          dlm Amazon Data Lifecycle Manager (DLM): Manage the lifecycle of AWS resources. Create lifecycle policies to automate operations on specified resources.
          ec2 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          ecr Amazon Elastic Container Registry (ECR) is a fully managed Docker container registry.
          ecs Amazon Elastic Container Service (ECS) is a highly scalable, fast, container management service.
          eks Amazon Elastic Kubernetes Service (EKS) is a managed service to run Kubernetes on AWS without own Kubernetes clusters.
          elasticache Set up, manage, and scale distributed in-memory cache environments in the AWS Cloud
          elasticbeanstalk Quickly deploy and manage applications in the AWS Cloud.
          elasticloadbalancing Automatically distribute incoming application traffic across multiple targets, such as EC2 instances. Also enables elasticloadbalancingv2.
          elasticmapreduce Amazon Elastic MapReduce (EMR) processes large amounts of data efficiently using Hadoop processing combined with several AWS products.
          email Amazon Simple Email Service (Amazon SES): An email platform to send and receive email using ones own email addresses and domains. See: //docs.aws.amazon.com/ses/latest/DeveloperGuide/Welcome.html
          es Amazon Elasticsearch Configuration Service (ES) is an API to create, configure, and manage Elasticsearch domains.
          events Serverless event bus service to connect applications with data from a variety of sources. Also enables eventbridge.
          fsx Amazon FSx is a fully managed service to launch and use shared file storage.
          global 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          AWS Global Accelerator is a network layer service for 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          s to improve availability and performance for internet applications used by a global audience.
          http Enable http support via curl
          iot AWS IoT This is a meta-flag for all Internet of Things modules provided by the SDK: iot : enables secure, bi-directional communication between Internet-connected things (such as sensors, actuators, embedded devices, or smart appliances) and the AWS Cloud over MQTT and HTTP. greengrass : Extends AWS onto physical devices so they can act locally on the data they generate. iot1click : A service for simple devices to trigger AWS Lambda functions that execute a specific action. iotanalytics : Provides advanced data analysis for AWS IoT. iotevents : Monitor equipment or device fleets for failures or changes in operation, and trigger actions when such events occur. iotthingsgraph: Integrated set of tools that enable developers to build IoT applications using devices and services that use different data representation standards and communication protocols. Also enables iot1click-devices, iot1click-projects, iot-data, iotevents-data and iot-jobs-data.
          kinesis Amazon Kinesis Collect, process, and analyze video and data streams in real time. The following modules besides kinesis are enabled: firehose : Load data streams into AWS data stores. kinesisanalytics : Process and analyze streaming data using SQL or Java. (Also enables kinesisanalyticsv2) kinesisvideo : Capture, process, and store video streams for analytics and machine learning. Additionally kinesis-video-archived-media and kinesis-video-media are enabled.
          kms AWS Key Management Service (KMS) An encryption and key management service scaled for the cloud.
          lambda AWS Lambda: Run code without provisioning or managing servers.
          lex Amazon Lex is an AWS service for building conversational interfaces into applications using voice and text. Also enables lex-models.
          license-manager Streamlines the process of bringing software vendor licenses to the cloud.
          lightsail The easiest way to get started with AWS for developers who just need virtual private servers
          machinelearning The algorithms of Amazon Machine Learning create machine learning (ML) models by finding patterns in existing data. The service uses these models to process new data and generate predictions for application.
          macie A security service that uses machine learning to automatically discover, classify, and protect sensitive data in AWS.
          managedblockchain Create and manage scalable blockchain networks using popular open source frameworks. Currently, Managed Blockchain supports the Hyperledger Fabric open source framework.
          marketplace 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          opsworks AWS OpsWorks is a simple and flexible way to create and manage stacks and applications. Also enables opsworkscm.
          organizations Account management service that to consolidate multiple AWS accounts into an organization to be centrally managed.
          other This is a meta-flag for rarely needed modules that in themselves need not much build time. If you would like to have any of the following modules to have their own USE flag, please open a bug report and it will most probably get one. The modules are: AWSMigrationHub, alexaforbusiness, clouddirectory, comprehend, comprehendmedical, connect, datapipeline, datasync, directconnect, discovery, dms, docdb, ds, dynamodb, gamelift, glue, groundstation, importexport, kafka, lakeformation, mq, mturk-requester, neptune, quicksight, redshift, robomaker, sdb, service-quotas, servicecatalog, servicediscovery, signer, sms, snowball, ssm, states, storagegateway, support and swf.
          personalize Real-time personalization and recommendations, based on the same technology used at Amazon.com. Also enables personalize-events and personalize-runtime.
          polly Amazon Polly A Text-to-Speech (TTS) cloud service that converts text into lifelike speech. Also enables text-to-speech.
          queues AWS Queues is a simple queue class. Allows standard queue operations top, delete, and push. Also has higher level, asynchronous interface with callbacks.
          rds Amazon Relational Database Service (RDS) is a web service to set up, operate, and scale a relational database in the cloud. Also enables pi (Performance Insights) and rds-data.
          rekognition Add image and video analysis to applications.
          resource-groups AWS Resource Groups and Tag Editor Organize AWS resources into groups, tag resources using virtually any criteria, and manage, monitor, and automate tasks on grouped resources. Also enables resourcegroupstaggingapi. (Resource Groups Tagging API)
          route53 AWS Route 53 is a highly available and scalable Domain Name System (DNS) web service. Also enables route53domains and route53resolver.
          rtti Flag to enable/disable rtti within the library
          s3 Amazon Simple Storage Service Storage for the internet. Additionally to the s3 module, the following modules are activated: Athena : Interactive query service to analyze data in Amazon S3 using standard SQL. Glacier : Storage solution for cold data. Transfer for SFTP: Transfer files directly into and out of Amazon S3 using SFTP. Also enables s3-encryption, s3control and transfer.
          sagemaker Amazon SageMaker Fully managed machine learning service. With Amazon SageMaker, data scientists and developers can quickly and easily build and train machine learning models, and then directly deploy them into a production-ready hosted environment. Also enables sagemaker-runtime.
          secretsmanager Encrypt, store, and retrieve credentials for databases and other services.
          securityhub Provides a comprehensive view of the security state of AWS resources.
          serverlessrepo AWS Serverless Application Repository Enables teams, organizations, and individual developers to find, deploy, publish, share, store, and easily assemble serverless architectures.
          shield AWS Shield, protection against DDoS attacks
          sns 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          sqs Amazon Simple Queue Service (SQS): Fully managed message queuing service that makes it easy to decouple and scale microservices, distributed systems, and serverless applications.
          textract Amazon Textract to add document text detection and analysis to applications.
          transcribe A transcription services for audio files. It uses advanced machine learning technologies to recognize spoken words and transcribe them into text. Also enables transcribestreaming.
          translate A neural machine translation service for translating text to and from English across a breadth of supported languages.
          unity-build Build using a single unified .cpp file for each service library. Reduces the size of static library binaries
          waf The Web Application Firewall (WAF) can monitor web requests that are forwarded to Amazon CloudFront distributions or an Application Load Balancer. Can also be used to block or allow requests based on conditions such as the IP addresses that requests originate from or values in the requests. Also enables fms and waf-regional.

          beignet

          ocl-icd Enable compatibility with the dev-libs/ocl-icd OpenCL ICD loader
          ocl20 Enable experimental OpenCL 2.0 support on Skylake and newer architectures

          bitset

          tcmalloc Use tcmalloc from dev-util/google-perftools for allocations

          boost

          context Build and install the Boost.Context (and Boost.Fiber) library and all other Boost libraries that depend on it
          debug Build and install only the debug version of the Boost libraries. Only enable this flag if you're developing against boost.
          doc 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          nls Build libboost_locale. This library requires compatible C library interfaces, which might not be provided by uClibc or other embedded libraries.
          numpy Optionally build NumPy extensions when Boost.Python is enabled
          threads Build multi-thread-compatible libraries instead of single-threaded only.
          tools Build and install the boost tools (bcp, quickbook, inspect, wave)

          botan

          boost use dev-libs/boost

          check

          subunit Enable support for the subunit unit test protocol

          crypto++

          asm Support assembly hand optimized crypto functions (i.e. faster run time)

          cyber 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          tools Build and install optional management tools.
          usb Enable support for usb based chipcard reader.

          cyrus-sasl

          authdaemond Add Courier-IMAP authdaemond unix socket support (net-mail/courier-imap, mail-mta/courier)
          ldapdb Enable ldapdb plugin
          openldap Add ldap support for saslauthd
          sample Enable sample client and server
          srp Enable SRP authentication
          urandom Use /dev/urandom instead of /dev/random

          dbus-c++

          ecore Use Ecore integration
          glib Use glib integration

          eekboard

          libcanberra Enable support for media-libs/libcanberra
          xtest Enable support for x11-libs/libXtst

          efl

          bmp Enable WBMP image loader
          dds Enable DDS image loader
          drm Enable DRM engine
          eet Enable Eet image loader
          fribidi Enable bidirectional text support
          gles2 Enable the OpenGL ES GL implementation
          glib Enable dev-libs/glib support
          harfbuzz Enable complex text shaping and layout support
          hyphen Enable text hyphenation support
          ibus Enable Intelligent Input Bus
          ico Enable Ico image loader
          json Enable lottie animation support
          libuv Enable dev-libs/libuv support
          luajit USE dev-lang/luajit instead of dev-lang/lua
          mono Enable mono bindings
          physics Enable Bullet physics effects and support
          pmaps Enable PMAPS image loader
          ppm Enable PMAPS image loader
          psd Enable PSD image loader
          scim Enable Smart Common Input Method
          system-lz4 Use system liblz4 instead of bundled one
          tga Enable Tga image loader
          tgv Enable Tgv image loader
          tslib Enable x11-libs/tslib for touchscreen events
          unwind Enable debug support via sys-libs/libunwind
          valgrind Enable usage of dev-util/valgrind in debug
          vlc Enable media-video/vlc support
          xcf Enable XCF image loader
          xim Enable X Input Method
          xpresent Enable x11-libs/libXpresent support

          elfutils

          lzma Support automatic decompression of LZMA-compressed files and kernel images
          threads Build the libraries with thread safe support
          utils Install command-line utilities (all the eu-* programs)
          valgrind Add support for memory debugging using dev-util/valgrind

          ell

          glib Enable dev-libs/glib support

          fcgi

          html Install HTML documentation

          folks

          telepathy Load contacts from the Telepathy framework
          tracker Load contacts from app-misc/tracker index
          utils Build the folks-inspect utility

          fstrm

          utils Build fstrm utility programs

          gf2x

          bindist Disable automatic fine-tuning to local processor features like pclmul or sse2.
          custom-tune Extra long compile time for tuning hardware specific low-level routines
          fft Build an FFT API for multiplication of 2 polynomials over GF(2)

          glib

          dbus Enable dependencies required by glib libraries using dbus service to manage settings saving
          mime 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          systemtap Build support for profiling and tracing using dev-util/systemtap
          utils Install gtester-report utility to generate test report files for your software; build gresource utility with ELF support.

          gmime

          smime Enable experimental S/MIME support

          gmp

          asm Enable use of hand optimized assembly routines (faster execution)

          gobject-introspection

          doctool Install g-ir-doc-tool for generating documentation from introspected data

          hidapi

          fox Build a x11-libs/fox GUI

          hsa-ext-rocr

          deprecated Install the deprecated debug/trace/profiling library

          input-pad

          eekboard Enable support for dev-libs/eekboard
          xtest Enable support for x11-libs/libXtst

          intel-neo

          vaapi Support the sharing of surfaces with Video Acceleration API (OpenCL Extension #36)

          jemalloc

          hugepages Enable transparent huge page support
          lazy-lock Enable lazy locking (only lock when multi-threaded)
          prof Enable allocation profiling
          stats Enable statistics calculation/reporting
          xmalloc Add support for xmalloc (abort-on-out-of-memory)

          kreport

          marble Enable displaying of maps using kde-apps/marble
          scripting Support Qml scripting using dev-qt/qtdeclarative

          libbase58

          tools Build command line base58 tool

          libbytesize

          tools Build bscalc python CLI tool

          libcdio

          minimal Only build the libcdio library and little more, just to be used to link against from multimedia players. With this USE flag enabled, none of the command-line utilities are built, nor is the CDDA library.

          libcec

          cubox Enable support for enable support for the TDA995x
          exynos Enable support for Exynos chipsets
          raspberry-pi Enable support for the Raspberry Pi
          xrandr Enable detection of active HDMI using xrandr extensions

          libcgroup

          daemon Install the configuration tools and init/config files.
          tools Install the cgroup rules processing daemon and init/config files.

          libclsync

          extra-debug Enable extra debugging. This will hurt performance badly. Be ready for tons of output.
          extra-hardened Enable extra security checks. This may hurt performance.

          libdbusmenu

          gtk Enable support for GTK+2
          gtk3 Enable support for GTK+3

          libdynd

          cuda Enable NVIDIA CUDA toolkit support
          mkl Enable a plugin for Intel Math Kernel Library sci-libs/mkl

          libevent

          debug Support runtime debug mode and malloc hooks (for programmers)

          libffi

          pax_kernel Use PaX emulated trampolines, for we can't use PROT_EXEC
          test-bhaible Run extended regression tests (very slow).

          libffi-compat

          pax_kernel Use PaX emulated trampolines, for we can't use PROT_EXEC

          libflatarray

          cuda Enables plugins for NVIDIA GPUs (e.g. CUDAAllocator)

          libgcrypt

          o-flag-munging Enable O-flag mangling during build

          libgdata

          crypt Use app-crypt/gcr for keeping tokens and passwords in non-pageable memory for improved security
          gnome-online-accounts Enable net-libs/gnome-online-accounts support

          libgit2

          gssapi Enable GSSAPI support for SPNEGO auth
          ssh Enable SSH transport support
          trace Enable tracing support

          libgit2-glib

          ssh Enable SSH transport support

          libgpg-error

          common-lisp Install common-lisp files

          libgpiod

          tools Build some useful gpio tools that use libgpiod.

          libgpuarray

          cuda Enable NVIDIA CUDA toolkit support
          opencl Enable OpenCL support

          libgweather

          glade Installs catalog files for dev-util/glade

          libical

          glib Enable dev-libs/glib interface support

          libisoburn

          external-filters Allow the use of external processes as file content filters (Note: this is a potential security risk)
          external-filters-setuid Also allow the use of external setuid processes as file content filters (Note: this is a potential security risk)
          frontend-optional Use dev-tcltk/bwidget which is not strictly required for the frontend
          launch-frontend Enable the tcl gui for xorriso
          launch-frontend-setuid Enable the tcl gui for xorriso under setuid

          libisofs

          verbose-debug Enable verbose debug messages

          liblogging

          rfc3195 Enables RFC 3195 protocol (aka syslog-reliable) support. If you don't know what this is, you don't need it!
          stdlog Enables liblogging's core component (think of it as a the next version of the syslog(3) API).

          libmemcached

          hsieh Use Hsieh hash algorithm.
          libevent Use the libevent event loop interface.
          sasl Use sasl auth for communications.

          libnfc

          pcsc-lite Enable NFC drivers that require pcsc-lite

          libnl

          doc Install development documentation
          python Install experimental dev-lang/python bindings
          utils Install command line interface utils

          liborcus

          spreadsheet-model Enable the spreadsheet model implementation
          tools Build various low-level parsers

          libowfat

          diet Compile against dev-libs/dietlibc

          libp11

          doc Generate and install API documentation for the package.

          libpcre

          bzip2 Add support for pcregrep command to search within bzip2-compressed files (via app-arch/bzip2).
          pcre16 Build PCRE library for 16 bit characters (e.g. UTF-16).
          pcre32 Build PCRE library for 32 bit characters (e.g. UTF-32).
          readline Add support for command line editing to pcretest, through sys-libs/readline.
          recursion-limit Limit match recursion to 8192; if disabled, the default limit is used, which is the same as the match limit.
          zlib Add support for pcregrep command to search within gzip-compressed files (via sys-libs/zlib).

          libpcre2

          bzip2 Add support for pcregrep command to search within bzip2-compressed files (via app-arch/bzip2).
          pcre16 Build PCRE library for 16 bit characters (e.g. UTF-16).
          pcre32 Build PCRE library for 32 bit characters (e.g. UTF-32).
          readline Add support for command line editing to pcretest, through sys-libs/readline.
          recursion-limit Limit match recursion to 8192; if disabled, the default limit is used, which is the same as the match limit.
          zlib Add support for pcregrep command to search within gzip-compressed files (via sys-libs/zlib).

          libpeas

          glade Install the glade catalog
          python Build support for loading dev-lang/python plugins

          librdkafka

          lz4 Enable support for Kafka's LZ4 compression based on KIP-57 (uses app-arch/lz4)

          librelp

          gnutls Use GnuTLS
          libressl Use LibreSSL
          openssl Use OpenSSL

          libressl

          asm Enables assembly

          libsecp256k1

          asm Enable x86_64 assembly optimisation
          ecdh Enable ECDH shared secret computation
          endomorphism Enable endomorphism
          experimental Allow experimental USE flags
          recovery Enable ECDSA pubkey recovery module
          schnorr Enable Schnorr signature module
          test-openssl Enable OpenSSL comparison tests

          libslz

          tools Install additional tools (zenc, zdec)

          libsodium

          asm Enables assembly implementations
          urandom Use /dev/urandom instead of /dev/random

          libspt

          libtirpc Build against net-libs/libtirpc for RPC support

          libtasn1

          valgrind Enable usage of dev-util/valgrind in debug

          libtermkey

          demos Install demos, which pulls in dev-libs/glib

          libunibreak

          doc Install html API documentation.
          man Generate man pages with doxygen.

          libverto

          glib Support event loops using dev-libs/glib
          libev Support event loops using dev-libs/libev
          libevent Support event loops using dev-libs/libevent
          tevent Support event loops using sys-libs/tevent

          libvoikko

          expvfst Enable experimental features of VFST morphology backend
          hfst Enable HFST morphology backend

          libxmlb

          stemmer Enable language stemming support

          libzia

          ftdi Enable support for FTDI USB chips

          libzip

          mbedtls Use net-libs/mbedtls as TLS provider
          aspell Adds support for app-text/aspell spell checker
          hunspell Adds support for app-text/hunspell spell checker

          log4cplus

          iconv Use inconv for wchar_t <-> char conversions. See also log4cplus's unicode.txt documentation
          working-c-locale Use the C99 locale facilities for wchar_t <-> char conversions. See also log4cplus's unicode.txt documentation
          working-locale Use C++'s std::locale for wchar_t <-> char conversions. See also log4cplus's unicode.txt documentation

          log4cxx

          smtp Offer SMTP support via net-libs/libesmtp

          m17n-lib

          X Build the Graphical User Interface API and utilities
          anthy Enable support for app-i18n/anthy input method
          athena 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          gd Build API and utilities based on media-libs/gd. This flag is only meaningful if the X USE flag is also enabled
          libotf Use dev-libs/libotf to handle OpenType fonts
          libxml2 Use dev-libs/libxml2 to parse XML

          msgpack

          boost Enable boost support

          nss

          cacert Include root/class3 certs from CAcert (//www.cacert.org/)
          nss-pem Add support for libnsspem
          utils Install utilities included with the library

          ocl-icd

          khronos-headers Install Khronos OpenCL headers.

          onigmo

          combination-explosion-check enable combination explosion check
          crnl-as-line-terminator enable CR+NL as line terminator

          oniguruma

          crnl-as-line-terminator enable CR+NL as line terminator

          opencryptoki

          tpm Enable support for Trusted Platform Module (TPM) using app-crypt/trousers

          openct

          debug Add debug output to the driver library for pcsc-lite.
          pcsc-lite Build a driver library for sys-apps/pcsc-lite, providing PC/SC API access to devices supported by OpenCT.

          openobex

          irda Enable IrDA support

          opensc

          ctapi Use CT-API for accessing Smartcard hardware
          notify Enable notifications
          openct Use dev-libs/openct (and CT-API) for accessing Smartcard hardware
          pcsc-lite Use sys-apps/pcsc-lite (and PC/SC API) for accessing Smartcard hardware
          secure-messaging Enable secure messaging

          openssl

          asm Support assembly hand optimized crypto functions (i.e. faster run time)
          bindist Disable/Restrict EC algorithms (as they seem to be patented) -- note: changes the ABI
          rfc3779 Enable support for RFC 3779 (X.509 Extensions for IP Addresses and AS Identifiers)
          sslv2 Support for the old/insecure SSLv2 protocol -- note: not required for TLS/https
          sslv3 Support for the old/insecure SSLv3 protocol -- note: not required for TLS/https
          tls-heartbeat Enable the Heartbeat Extension in TLS and DTLS

          openssl-compat

          asm Support assembly hand optimized crypto functions (i.e. faster run time)
          bindist Disable/Restrict EC algorithms (as they seem to be patented) -- note: changes the ABI
          rfc3779 Enable support for RFC 3779 (X.509 Extensions for IP Addresses and AS Identifiers)
          sslv2 Support for the old/insecure SSLv2 protocol -- note: not required for TLS/https
          sslv3 Support for the old/insecure SSLv3 protocol -- note: not required for TLS/https
          tls-heartbeat Enable the Heartbeat Extension in TLS and DTLS

          pkcs11-helper

          nss Enable NSS crypto engine

          poco

          7z Add Support for the 7z archive format
          cppparser 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          crypto Encryption and digital signing classes
          data Database abstraction layer to easily send/retrieve data to/from various databases
          file2pagecompiler Utility to convert ordinary files to Page Compiler source files
          json Add JSON support
          mariadb Prefer dev-db/mariadb-connector-c over dev-db/mysql-connector-c
          mongodb Add dev-db/mongodb support
          net Classes to write network clients & servers
          pagecompiler Simple compiler translating HTML pages containing embedded C++ code into HTTPRequestHandler classes
          pocodoc POCO documentation generator
          util Several utility classes (like logger, timer, config file parser)
          zip Add support for the zip & gz archive formats

          ppl

          lpsol Build the ppl_lpsol linear programming problem solver

          rocr-runtime

          nonfree Enables HSA image support using dev-libs/hsa-ext-rocr

          serdisplib

          tools Build optional tools.

          softhsm

          gost Enable gost algorithm
          migration-tool Build db migration tool

          starpu

          cuda Enable NVIDIA CUDA toolkit support
          gcc-plugin Enable GCC extension plugin (experimental)
          opencl Enable OpenCL support
          spinlock-check Enable spinlock check
          valgrind Enable dev-util/valgrind support

          stp

          python Enable building the Python interface

          tinyxml

          stl Compile with TIXML_USE_STL support

          tntnet

          server Enable tntnet server daemon

          totem-pl-parser

          archive Enables ISO detection with app-arch/libarchive
          crypt Support AmazonAMZ decoding with dev-libs/libgcrypt
          quvi Use media-libs/libquvi for parsing video links

          tvision

          gpm Support text mode mouse through sys-libs/gpm

          ucommon

          socks Build with socks proxy support

          userspace-rcu

          regression-test Run regression tests (requires FEATURES=test)

          ustr

          ustr-import Install ustr-import developer program and source code for bundling.

          weston

          desktop Enable the desktop shell
          drm Enable drm compositor support
          editor Install wayland-editor example application
          fbdev Enable fbdev compositor support
          fullscreen Enable fullscreen/kiosk shell
          gles2 Use GLESv2 cairo instead of full GL
          headless Headless backend and a noop renderer, mainly for testing purposes
          ivi Enable the IVI shell
          launch Install weston-launch utility
          500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          Enable virtual remote output with Pipewire on DRM backend
          rdp Enable Remote Desktop Protocol compositor support
          remoting Enable plugin to stream output to remote hosts using media-libs/gstreamer
          resize-optimization Increase performance, allocate more RAM. Recommended to disable on Raspberry Pi
          screen-sharing Enable screen-sharing through RDP
          unwind Enable libunwind usage for backtraces
          wayland-compositor Enable Wayland compositor support
          xwayland Enable ability support native X11 applications

          xapian

          brass Enabled brass backend db support
          chert Enabled chert backend db support
          glass Enabled glass backend db support
          inmemory Enabled inmemory backend db support
          remote Enabled remote backend db support

          xerces-c

          iconv Use iconv (virtual/libiconv) as message loader and transcoder (in general it would be possible to use iconv only as message loader and something else like icu or the native method as transcoder and vice-versa, but this is a less common case and hard to handle)
          threads Enable threading support through pthread (or other libraries on AIX, IRIX, HPUX, Solars). Highly recommended

          xmlrpc-c

          abyss Build the Abyss mini web-server.
          libxml2 Use dev-libs/libxml2 to parse XML instead of the internal expat library.
          threads Controls whether to build the Abyss web-server with pthreads or fork 'threading'.
          tools Build the xmlrpc* tools.

          xmlsec

          gcrypt Install xmlsec-gcrypt library
          gnutls Install xmlsec-gnutls library
          nss Install xmlsec-nss library
          openssl Install xmlsec-openssl library

          yaz

          ziffy Install ziffy, a promiscuous Z39.50 APDU sniffer

          dev-lisp

          clisp

          hyperspec Use local hyperspec instead of online version
          svm Build CLISP with support for the Support Vector Machine module

          clx

          doc Builds documentation

          cmucl

          X Build CLX, CLM, or Hemlock
          doc Installs package documentation
          source Include source code for CMUCL in installation

          ecls

          gengc Use generational garbage collection (experimental)
          libatomic Use dev-libs/libatomic_ops library
          precisegc Use type information during garbage collection (experimental)

          gcl

          ansi Build a GCL with ANSI support (else build a traditional CLtL1 image)
          athena Build xgcl - an interface to x11-libs/libXaw

          sbcl

          pax_kernel Enable if the user plans to run the package under a pax enabled hardened kernel

          dev-lua

          lua-cjson

          internal-fpconv Enable internal number conversion routines, can increase overall performance by up to 50%

          luarocks

          curl Uses net-misc/curl for fetching lua packages instead of net-misc/wget.
          openssl Uses dev-libs/openssl for verifying lua packages instead of md5sum.

          dev-ml

          cairo-ocaml

          pango Enable support for x11-libs/pango

          csv

          lwt Enables the Lwt-based library for asynchronous operations.

          dose3

          parmap Adds multi-core CPU support via dev-ml/parmap.
          rpm4 Adds support for handling rpm4 files.
          zip Adds support for handling zip files.

          eliom

          ppx Enable PPX syntax extension support.

          js_of_ocaml

          camlp4 Build with camlp4 syntax extensions.
          deriving Enable dev-ml/deriving support for improving the type safety.
          lwt Enable dev-ml/lwt support.
          ppx Enables the ppx syntax extension
          react Enable functionnal reactive programming support.

          lablgtk

          glade Enable libglade bindings compilation.
          gnomecanvas Enable libgnomecanvas bindings compilation.
          sourceview Enable GtkSourceView support

          logs

          cli Enables the Logs_cli library that provides command line support for controlling Logs.
          fmt Enables the Logs_fmt reporter.
          lwt Enables the Logs_lwt library that provides Lwt logging functions.

          lwt

          camlp4 Enable camlp4 syntax extension
          libev Enable the dev-libs/libev-based backend.
          ppx Enables the ppx syntax extension

          ocaml-cohttp

          async Enables support for the dev-ml/async asynchronous execution library.
          lwt Enables support for the dev-ml/lwt cooperative light-weight thread library.

          ocaml-cstruct

          async Support for asynchronous execution
          lwt Enable threads via lwt
          ppx Enable the ppx syntax extension

          ocaml-websocket

          async Enables support for the dev-ml/async asynchronous execution library.
          lwt Enables support for the dev-ml/lwt cooperative light-weight thread library.

          ocamlnet

          httpd Enables net-httpd web server component
          zip Enables netzip support to read/write gzip data using object channels

          onanomsg

          lwt Enables lwt support.

          pgocaml

          camlp4 Enable PG'Ocaml syntax extension.

          tyxml

          camlp4 Enables the camlp4 syntax extension (deprecated)
          ppx Enables the ppx syntax extension (preferred)

          uutf

          utftrip Builds and install the utftrip executable: Among other things, reads unicode on stdin and rewrites it on stdout.

          zarith

          mpir Use MPIR library instead of GMP.

          dev-perl

          App-Nopaste

          browser Spawn browser with pasted page
          clipboard copying of URLs with -x/--copy
          github Github authentication
          500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          Ensure git is installed for reading/passing GitLab authentication
          pastebin pastebin.com support

          Boulder

          genbank Provide support with Boulder::Genbank for decoding Genbank data records
          store Provide support with Boulder::Store for persisting Stone objects

          Business-ISBN

          barcode Install dev-perl/GD-Barcode for rendering ISBN numbers as barcodes

          Config-Any

          conf Install dev-perl/Config-General to support decoding .conf/.cnf files
          ini Install dev-perl/Config-Tiny to support decoding INI config files
          json Install support libraries to support decoding JSON config files
          xml Install support libraries to support decoding XML config files
          yaml Install support libraries to support decoding YAML config files

          Convert-UUlib

          system-uulib Use dev-libs/uulib instead of bundled version.

          Cookie-Baker

          xs Install dev-perl/Cookie-Baker-XS for accelerated performance

          Coro

          ev Build support for using dev-perl/EV as an event-loop via Coro::EV
          event Build support for using dev-perl/Event as an event-loop via Coro::Event

          DBD-MariaDB

          mariadb Use dev-db/mariadb-connector-c as the client library
          mysql Use dev-db/mysql-connector-c as the client library

          DBD-SQLite

          system-sqlite Use the system-wide dev-db/sqlite installation

          DBD-mysql

          mariadb Use dev-db/mariadb-connector-c as the client library
          mysql Use dev-db/mysql-connector-c as the client library
          ssl Compile in support for SSL connections via libmysqlclient

          DBIx-Class

          admin Modules required for the DBIx::Class administrative library
          admin-script Modules required for the CLI DBIx::Class interface dbicadmin
          deploy Modules required for "deploy" in DBIx::Class::Storage::DBI and "deploymen_statements" in DBIx::Class::Storage::DBI
          replicated Modules required for DBIx::Class::Storage::DBI::Replicated

          File-HomeDir

          xdg Ensure XDG Semantics for returned paths via x11-misc/xdg-user-dirs

          File-Which

          pwhich Install dev-perl/App-pwhich which used to be a part of this package

          GD

          animgif Enable animated gif support
          fcgi Build for FastCGI compatibility via dev-libs/fcgi instead of using PerlIO

          Graphics-ColorNames

          recommended Install recommended support modules

          HTML-Mason

          modperl Enable www-apache/mod_perl support

          HTTP-Entity-Parser

          xs Install C-Based dependieces for faster performance

          JSON

          xs Install C-based dev-perl/JSON-XS for faster performance

          JSON-MaybeXS

          xs Install a C-Based backend to make JSON encode/decode fast

          Lab-VXI11

          libtirpc Build against net-libs/libtirpc for RPC support

          List-MoreUtils

          xs Install C-Based backend implementation for performance

          MCE

          sereal Install dev-perl/Sereal-Encoder and decoder for faster worker IPC

          Mail-IMAPClient

          md5 Install support for DIGEST-MD5 and CRAM-MD5 Authentication
          ntlm Install support for NTLM Authentication
          ssl Install support for SSL Connections
          zlib Install support for COMPRESS DEFLATE connections

          Net-SSH2

          gcrypt Use libgcrypt instead of openssl

          PDL

          badval Enable bad values support
          hdf Enable HDF (version 4) format support
          netpbm Enable NETPBM and MPEG support
          pdl2 Build pdf2 shell (requires Devel-REPL)
          pgplot Enable PGPLOT plotting capabilities

          Panotools-Script

          gui Installs GUIs for some tools

          Ref-Util

          xs Install C-Based dev-perl/Ref-Util-XS for accelerated performance

          Sub-Name

          suggested Install extra dependencies needed for extended regression tests

          Sysadm-Install

          hammer Enable hammer() funtion to run a command in the shell and simulate a user hammering the ENTER key to accept defaults on prompts

          Test-Warnings

          suggested Install optional dependencies for extra tests

          Text-CSV

          xs Install dev-perl/Text-CSV_XS for accelerated decoding

          WWW-Form-UrlEncoded

          xs Install C-Based dependieces for faster performance

          perl-headers

          debug Add source locations in generated .ph files to assist with debugging when errors occur
          sizeof-warning Include logic to warn when a .ph file tries to use a sizeof() that is unknown

          dev-php

          PEAR-HTTP_Request2

          curl Force dev-lang/php to be compiled with curl extension
          fileinfo Force dev-lang/php to be compiled with fileinfo extension
          ssl Force dev-lang/php to be compiled with ssl extension
          zlib Force dev-lang/php to be compiled with zlib extension

          PEAR-PHP_Beautifier

          cli Require dev-lang/php to be built with the "cli" SAPI and install the php_beautifier script.

          agavi

          executable Install the "agavi" executable used to manage projects. This requires dev-php/phing, and may be omitted if you are (for example) deploying an existing site to a production server.

          maxmind-db-reader

          extension Build the C extension that uses dev-libs/libmaxminddb

          pecl-apcu

          lock-pthreadmutex Enable pthread mutex locking
          lock-pthreadrw Enable pthread read/write locking
          lock-semaphore Enable semaphore locks instead of fcntl
          lock-spinlock Enable spin locks (EXPERIMENTAL)

          pecl-event

          extra Add support of the Libevent extra API

          pecl-memcached

          igbinary Enable support for the igbinary serializer
          json Enable support for json serialization

          pecl-mysqlnd_qc

          memcached Use dev-libs/libmemcached as a storage handler
          sqlite Use dev-db/sqlite as a storage handler

          pecl-redis

          igbinary Enables igbinary serialisation support
          json Enables json serializer support

          pecl-zmq

          czmq Use the czmq high level bindings

          phing

          zip Support zip archives by requiring said support in dev-lang/php.

          swoole

          http2 Add support for HTTP/2 protocol via net-libs/nghttp2

          xcache

          coverage Enable the coverager module (not recommended for production servers).

          dev-python

          Kivy

          camera Install libraries needed to support camera
          garden Install garden tool to manage user maintained widgets

          PyQt5

          bluetooth Build bindings for the QtBluetooth module
          dbus Build bindings for the QtDBus module
          declarative Build bindings for the QtQml/QtQuick modules and enable the qmlscene plugin
          designer Build bindings for the QtDesigner module and enable the designer plugin
          gles2 Use GLES 2.0 or later instead of full OpenGL
          gui Build bindings for the QtGui module
          help Build bindings for the QtHelp module
          location Build bindings for the QtLocation module
          multimedia Build bindings for the QtMultimedia module
          network Build bindings for the QtNetwork module
          networkauth Build bindings for the QtNetworkAuth module
          opengl Build bindings for the QtOpenGL module
          positioning Build bindings for the QtPositioning module
          printsupport Build bindings for the QtPrintSupport module
          sensors Build bindings for the QtSensors module
          serialport Build bindings for the QtSerialPort module
          sql Build bindings for the QtSql module
          svg Build bindings for the QtSvg module
          testlib Build bindings for the QtTest module
          webchannel Build bindings for the QtWebChannel module
          webengine Build bindings for the QtWebEngine module
          webkit Build bindings for the QtWebKit module
          websockets Build bindings for the QtWebSockets module
          widgets Build bindings for the QtWidgets module
          x11extras Build bindings for the QtX11Extras module
          xmlpatterns Build bindings for the QtXmlPatterns module

          PythonQt

          extensions Install extensions

          QtPy

          designer Build bindings for the QtDesigner module and enable the designer plugin
          gui Build bindings for the QtGui module
          svg Build bindings for the QtSvg module
          testlib Build bindings for the QtTest module
          webengine Build bindings for the QtWebEngine module
          webkit Build bindings for the QtWebKit module

          amqplib

          extras Install extra tools to generate initial Python mod from an AMQP XML file

          anyvc

          bazaar Add support for Bazaar
          mercurial Add support for Mercurial

          celery

          redis Enables redis support
          sqs Enables Amazon SQS transport module for celery
          yaml Enable support of yaml as a configuration file format

          cryptography

          idna enable support for the old, deprecated IDNA specification (RFC 3490)

          ctypescrypto

          gost Build with support for GOST Message Authentication Code

          cvxopt

          dsdp Use interior point library sci-libs/dsdp
          glpk Use GNU Linear Programming Kit sci-mathematics/glpk

          dap

          server Enable OpenDAP server support

          dask

          distributed Add support for distributed computing with dev-python/distributed

          drf-yasg

          validation Enable swagger spec validation using swagger-spec-validator

          editorconfig-core-py

          cli Install command line interface as well as python library

          fabric

          fab2 Install as "fab2", allowing side-by-side install with fabric 1.x

          falcon

          cython Build cython-based python modules

          fastparquet

          brotli Enable support for brotli compression

          flask-restful

          paging Enable resource paging support

          geopy

          timezone Enables localized date support
          yahoo Enables use of YahooPlaceFinder

          glance_store

          cinder enable cinder backend supprt
          swift enable swift backend supprt
          vmware enable vmware backend supprt

          gmpy

          mpir Use sci-libs/mpir as gmp implementation

          icalendar

          doc Generate examples and other extra documentation

          ipython

          matplotlib Add support for dev-python/matplotlib
          nbconvert Enable support for converting notebooks to various formats using app-text/pandoc
          notebook Install requirements for the web notebook based on www-servers/tornado

          jira

          jirashell Include dependencies for jirashell (ipython, oauthlib)
          kerberos Support Kerberos authentication
          oauth Support OAuth authentication

          kazoo

          gevent Enable support for the gevent based handler

          kombu

          mongodb Enables MongoDB backend
          msgpack Enables MessagePack (de)serializer for Python
          redis Enables Redis backend
          sqs Enables Amazon SQS transport module for Kombu
          yaml Enables yaml backend

          markdown

          pygments Enable fancy pygments support

          matplotlib

          excel Pull dev-python/xlwt for the exceltools toolkit
          gtk2 Enable x11-libs/gtk+:2 support
          gtk3 Enable x11-libs/gtk+:3 support

          mpmath

          matplotlib Add support for dev-python/matplotlib

          msgpack

          native-extensions Compiles native "C" extensions (speedups, instead of using python fallback code).

          nbdime

          webtools Install web-based diff and merge tools.

          netaddr

          cli Enable netaddr shell with dev-python/ipython

          networkx

          extras Provide graph drawing and graph layout algorithms along with shapefile format reading and writing
          pandas Provides a DataFrame, which is a tabular data structure with labeled axes
          scipy Enables scipy backend
          yaml Provides YAML format reading and writing

          nltk

          numpy Use numpy for the saved word tokenizer

          nose

          coverage Pull in dev-python/coverage needed for nose-xcover plugin.

          numexpr

          mkl Enable support for Intel Vector Math Library, part of sci-libs/mkl.

          pandas

          full-support Pull all packages to give pandas full support

          paramiko

          server Enable server feature

          passlib

          bcrypt bcrpyt hash algoryptm support
          scrypt accelerated scrypt algoythm support
          totp time based one time password support

          paste

          flup enable support for flup (and therefore for various wgsi servers and middleware)
          openid enable OpenID support

          pillow

          imagequant Build with Image Quantization Library support

          py-amqp

          extras Install extra tools to generate initial Python mod from an AMQP XML file

          pygame

          midi Enable midi support using media-libs/portmidi

          pygpu

          cuda Enable NVIDIA CUDA toolkit support
          opencl Enable OpenCL support

          pyilmbase

          numpy Add bindings for dev-python/numpy use.

          pyocr

          cuneiform Enable support for the app-text/cuneiform OCR engine
          tesseract Enable support for the app-text/tesseract OCR engine

          pypax

          ptpax Enable PT_PAX_FLAGS support.
          xtpax Enable XATTR_PAX_FLAGS support.

          pypy

          low-memory Build using PyPy with the engine configured towards low memory footprint. This makes it possible to build PyPy using ~3.5G of RAM on amd64 and ~half of that on x86, at the cost of lengthened build time.
          sandbox Enable sandboxing functionality

          pypy3

          low-memory Build using PyPy with the engine configured towards low memory footprint. This makes it possible to build PyPy using ~3.5G of RAM on amd64 and ~half of that on x86, at the cost of lengthened build time.
          sandbox Enable sandboxing functionality

          python-mpd

          twisted Enable twisted support

          python-stdnum

          vies Enable VIES

          pyudev

          pygobject Install PyGobject bindings
          qt5 Install PyQt5 bindings

          pyyaml

          libyaml enable support for C implementation using libyaml

          pyzor

          gdbm Enables the Gdbm back-end database engine for pyzord
          gevent Use dev-python/gevent to enable asynchronous operation
          mysql Enables the MySQL back-end database engine for pyzord through dev-python/mysql-python. Only works with python-2.x!
          pyzord Enable the pyzord server daemon
          redis Enables the redis back-end database engine for pyzord through dev-python/redis-py

          rarfile

          compressed Enables the module to support compressed v3 archives by calling the app-arch/unrar.

          rdflib

          redland enable support for Redland triplestore

          restkit

          cli Install the restcli command line interface/tool, based on dev-python/ipython

          rfc3986

          idna enable support for the IDNA specification (RFC 5891)

          setuptools_scm

          mercurial Enables mercurial backend

          simplespectral

          faster Use sci-libs/scipy to speed up drawing
          fastest Use dev-python/pyFFTW to speed up drawing to the max

          sphinx

          net enable internet capabilities

          spyder

          webengine Build bindings for the QtWebEngine module

          sympy

          imaging Add support for dev-python/pillow
          ipython Add support for dev-python/ipython
          mathml Add support for mathml
          pyglet Use dev-python/pyglet for plots and print preview
          symengine Add support for a dev-python/symengine backend
          texmacs Add app-office/texmacs interface
          theano Add support for dev-python/theano

          tappy

          yaml Pull dependencies needed to support YAML blocks associated with test results.

          tinyrpc

          gevent Add support for gevent
          httpclient Add support for httpclient
          jsonext Add support for jsonext
          websocket Add support for websocket
          wsgi Add support for wsgi
          zmq Add support for zmq

          translate-toolkit

          html Support conversion between po and html files
          ical Support conversion between po and ical files
          ini Support conversion between po and ini files
          subtitles Support conversion between po and sub files
          yaml Support YAML format

          twisted

          conch include Twisted SSHv2 implementation
          http2 include http2 support
          serial include serial port support

          twisted-core

          serial include serial port support

          urllib3

          brotli Enable support for brotli compression

          vatnumber

          vies Enable VIES

          ws4py

          client Install client modules
          server Install server modules

          wxpython

          examples Install interactive demo module browser and sample applets.

          zeep

          async Add async support
          tornado Add tornado support

          zsi

          twisted add support for python-twisted (needs dev-python/twisted-core and dev-python/twisted-web)

          dev-qt

          designer

          declarative Build the qdeclarativeview plugin
          webkit Build the qwebview plugin

          linguist-tools

          qml Enable QML support in lupdate

          qdoc

          qml Enable QML/JS parsing support

          qt-creator

          android Build plugin for Android devices
          autotest Enable integration with popular unit testing frameworks (QtTest, Google Test, Boost.Test)
          autotools Enable autotools project manager plugin
          baremetal Build plugin for bare metal devices
          bazaar Add support for dev-vcs/bzr version control system
          beautifier Build the beautifier plugin (supports astyle, clang-format, and uncrustify)
          boot2qt Build plugin for Boot2Qt devices
          clang Build clang-based plugins (code model, formatting, refactoring, static analysis)
          clearcase Add support for IBM ClearCase version control system (requires manual installation of ClearCase client)
          cmake Enable cmake project manager plugin
          cppcheck Enable integration with dev-util/cppcheck
          ctfvisualizer Build the Chrome Trace Format visualizer plugin
          designer Enable designer for QtWidgets-based UIs
          glsl Enable GLSL editor
          help Enable the integrated documentation viewer
          ios Build plugin for Apple iOS devices
          lsp Add support for the Language Server Protocol (LSP)
          mcu Build plugin for MCU devices
          mercurial Add support for dev-vcs/mercurial version control system
          modeling Enable graphical model editor
          nim Build plugin for Nim language support
          perforce Add support for Perforce version control system (requires manual installation of Perforce client)
          perfprofiler Build the Linux Perf-based profiler plugin
          python Build plugin for Python language support
          qbs Enable QBS project manager plugin
          qmldesigner Enable designer for QML/QtQuick-based UIs
          qmlprofiler Build the QML profiler plugin
          qnx Build plugin for QNX devices
          remotelinux Add support for deployment and execution on a remote Linux host
          scxml Enable graphical SCXML editor
          serialterminal Build serial terminal plugin
          silversearcher Enable integration with sys-apps/the_silver_searcher
          systemd Add support for retrieving application output from journald
          valgrind Enable integration with dev-util/valgrind
          webassembly Build WebAssembly plugin
          webengine Use dev-qt/qtwebengine to view documentation
          winrt Build plugin for WinRT devices

          qt-docs

          3d Install documentation for dev-qt/qt3d
          assistant Install documentation for dev-qt/assistant
          bluetooth Install documentation for dev-qt/qtbluetooth
          charts Install documentation for dev-qt/qtcharts
          concurrent Install documentation for dev-qt/qtconcurrent
          core Install documentation for dev-qt/qtcore
          datavis Install documentation for dev-qt/qtdatavis3d
          declarative Install documentation for dev-qt/qtdeclarative
          designer Install documentation for dev-qt/designer
          gamepad Install documentation for dev-qt/qtgamepad (available in qt overlay only)
          graphicaleffects Install documentation for dev-qt/qtgraphicaleffects
          gui Install documentation for dev-qt/qtgui
          help Install documentation for dev-qt/qthelp
          html Install documentation in HTML format
          imageformats Install documentation for dev-qt/qtimageformats
          linguist Install documentation for dev-qt/linguist
          location Install documentation for dev-qt/qtlocation
          multimedia Install documentation for dev-qt/qtmultimedia
          network Install documentation for dev-qt/qtnetwork
          networkauth Install documentation for dev-qt/qtnetworkauth
          positioning Install documentation for dev-qt/qtpositioning
          printsupport Install documentation for dev-qt/qtprintsupport
          qch Install documentation in QCH format
          qdoc Install documentation for dev-qt/qdoc
          quickcontrols Install documentation for dev-qt/qtquickcontrols
          quickcontrols2 Install documentation for dev-qt/qtquickcontrols2
          script Install documentation for dev-qt/qtscript
          scxml Install documentation for dev-qt/qtscxml
          sensors Install documentation for dev-qt/qtsensors
          serialbus Install documentation for dev-qt/qtserialbus
          serialport Install documentation for dev-qt/qtserialport
          speech Install documentation for dev-qt/qtspeech
          sql Install documentation for dev-qt/qtsql
          virtualkeyboard Install documentation for dev-qt/qtvirtualkeyboard
          webchannel Install documentation for dev-qt/qtwebchannel
          webengine Install documentation for dev-qt/qtwebengine
          websockets Install documentation for dev-qt/qtwebsockets
          webview Install documentation for dev-qt/qtwebview
          widgets Install documentation for dev-qt/qtwidgets
          x11extras Install documentation for dev-qt/qtx11extras
          xmlpatterns Install documentation for dev-qt/qtxmlpatterns

          qt3d

          gamepad Add support for gamepad hardware via dev-qt/qtgamepad
          gles2 Use GLES 2.0 or later instead of full OpenGL
          qml Build QML/QtQuick bindings

          qtbluetooth

          qml Build QML/QtQuick bindings and imports

          qtcharts

          qml Build QML/QtQuick bindings and imports

          qtcore

          systemd Enable native journald logging support

          qtdatavis3d

          gles2 Use GLES 2.0 or later instead of full OpenGL
          qml Build QML/QtQuick bindings and imports

          qtdeclarative

          gles2 Use GLES 2.0 or later instead of full OpenGL
          localstorage Build the LocalStorage import for QtQuick (requires QtSql)
          widgets Enable QtWidgets support

          qtdiag

          network Report network information
          widgets Report widget style information

          qtgamepad

          evdev Enable support for input devices via evdev
          qml Build QML bindings

          qtgui

          egl Enable EGL integration
          eglfs Build the EGL Full Screen/Single Surface platform plugin
          evdev Enable support for input devices via evdev
          gles2 Use GLES 2.0 or later instead of full OpenGL
          ibus Build the IBus input method plugin
          libinput Enable support for input devices via dev-libs/libinput
          tslib Enable support for touchscreen devices via x11-libs/tslib
          tuio Build plugin to receive touch events over the TUIO protocol
          wayland Provide dev-qt/qtwayland to ensure Qt applications can be run as Wayland clients
          xcb Build the XCB platform plugin and enable X11 integration

          qtmultimedia

          gles2 Use GLES 2.0 or later instead of full OpenGL
          gstreamer Enable audio support via media-libs/gstreamer using SLOT 1.0
          qml Build QML/QtQuick bindings and imports
          widgets Build the QtMultimediaWidgets module

          qtnetwork

          bindist Disable EC support via dev-libs/openssl
          connman Enable net-misc/connman-based bearer plugin
          libproxy Use net-libs/libproxy for automatic HTTP/SOCKS proxy configuration
          networkmanager Enable net-misc/networkmanager-based bearer plugin

          qtopengl

          gles2 Use GLES 2.0 or later instead of full OpenGL

          qtpositioning

          geoclue Use enhanced location information from app-misc/geoclue
          qml Build QML bindings

          qtprintsupport

          gles2 Use GLES 2.0 or later instead of full OpenGL

          qtquickcontrols

          widgets Enable QtWidgets support

          qtquickcontrols2

          widgets Enable QtWidgets support

          qtscript

          scripttools Build the QtScriptTools module (requires QtWidgets)

          qtsensors

          qml Build QML bindings

          qtvirtualkeyboard

          handwriting Adds handwriting recognition integration support

          qtwayland

          libinput Enable support for input devices via dev-libs/libinput

          qtwebchannel

          qml Build QML/QtQuick bindings and imports

          qtwebengine

          designer Install the QWebEngineView plugin used to add widgets in dev-qt/designer forms that display web pages.
          geolocation Enable physical position determination via dev-qt/qtpositioning
          jumbo-build Combine source files to speed up build process.
          pax_kernel Enable building under a PaX enabled kernel
          system-ffmpeg Use the system-wide media-video/ffmpeg instead of bundled.
          system-icu Use the system-wide dev-libs/icu instead of bundled.
          widgets Enable QtWidgets support

          qtwebkit

          geolocation Enable physical position determination via dev-qt/qtpositioning
          gles2 Use GLES 2.0 or later instead of full OpenGL
          gstreamer Enable HTML5 audio/video support via media-libs/gstreamer using SLOT 1.0
          hyphen Enable hyphenation support via dev-libs/hyphen
          multimedia Enable HTML5 audio/video support via dev-qt/qtmultimedia
          orientation Enable device orientation detection via dev-qt/qtsensors
          printsupport Enable printing via dev-qt/qtprintsupport
          qml Build QML/QtQuick bindings

          qtwebsockets

          qml Build QML bindings

          qtwidgets

          gles2 Use GLES 2.0 or later instead of full OpenGL

          qtxmlpatterns

          qml Build the XmlListModel import for QtQuick (requires QtDeclarative)

          dev-ros

          rosbag

          lz4 Add support for lz4 compressed bags.

          rosconsole

          glog Use dev-cpp/glog as log backend.
          log4cxx Use dev-libs/log4cxx as log backend.

          dev-ruby

          barby

          cairo Add support for writing images (PNG, PS, EPS and, if supported, PDF and SVG) using dev-ruby/rcairo. Not available on JRuby.
          png Add support for writing PNG images using dev-ruby/chunky_png.
          prawn Add support for writing PDF documents using dev-ruby/prawn.
          qrcode Add support for QRCode 2D codes using dev-ruby/rqrcode.
          rmagick Add support for writing images (among others PNG, GIF and JPEG) using dev-ruby/rmagick. Not available on JRuby.

          faraday_middleware

          mashify Include FaradayMiddleware::Mashify
          oauth Include FaradayMiddleware::OAuth
          parsexml Include FaradayMiddleware::ParseXml
          rashify Include FaradayMiddleware::Rashify

          maruku

          highlight Enable source code highlighting via dev-ruby/syntax

          mysql2

          mariadb Use mariadb bindings

          net-ssh

          ed25519 Use dev-ruby/ed25519 for Ed25519 support
          sodium Use dev-libs/libsodium via dev-ruby/rbnacl for Ed25519 support

          rails

          asset-pipeline Also install the default components for the asset pipeline. These are not required but they are activated automatically in new Rails projects by default.

          rrdtool-bindings

          graph Enable support for graphing functions

          rspec-core

          highlight Enable source code highlighting via dev-ruby/coderay

          ruby-sdl

          image Enable media-libs/sdl-image support
          mixer Enable media-libs/sdl-mixer support
          sge Enable sdl-sge support

          rubygems

          server Install support for the rubygems server

          dev-scheme

          gauche

          mbedtls Enable support for net-libs/mbedtls

          gauche-gl

          cg Enable NVidia Cg binding

          gauche-gtk

          glgd Enable GL graph draw

          guile

          debug-freelist Include garbage collector freelist debugging code
          debug-malloc Include malloc debugging code
          deprecated Enable deprecated features
          discouraged (implied by deprecated) enable merely discouraged features
          networking Include networking interfaces
          regex Include regular expression interfaces

          kawa

          awt Assume AWT is available
          frontend Build "kawa" front-end program using sys-libs/readline
          jemacs Build JEmacs
          krl Build BRL emulation and KRL
          sax Assume SAX2 is available with dev-java/sax
          servlets Build support for generating servlets with Java servletapi
          swing Assume Swing is available
          xqtests Support XQuery Test Suite

          racket

          futures Enable racket/future library for fine-grained hardware parallelism
          places Enable racket/place library for share-nothing parallelism and message-passing communication. Compared to futures, places are heavyweight, but they have a simpler performance model.
          threads Enable support for green threads

          scm

          arrays Support for arrays, uniform-arrays and uniform-vectors.
          bignums Support for large precision integers.
          cautious SCM will always check the number of arguments to interpreted closures.
          dynamic-linking Be able to load compiled files while running.
          engineering-notation Floats to display in engineering notation (exponents always multiples of 3) instead of scientific notation.
          gsubr generalized c arguments: for arbitrary (more then 11) arguments to C functions.
          inexact Support for floating point numbers.
          ioext Commonly available I/O extensions: line I/O, file positioning, file delete and rename, and directory functions.
          libscm Build and install libscm.a and related headers
          macro C level support for hygienic and referentially transparent macros (syntax-rules macros).
          regex String regular expression matching.
          unix Support for: nice, acct, lstat, readlink, symlink, mknod and sync.

          slib

          gambit Support for gambit scheme implementation
          scm Support for scm scheme implementation

          dev-tcltk

          expect-lite

          debug pull in packages needed for runtime interactive debugger

          tcl3d

          ode Enable support for physics engine from dev-games/ode
          osg Enable support for 3D toolkit from dev-games/openscenegraph

          tktreectrl

          shellicon shellicon extension

          dev-tex

          abntex

          lyx Install with app-office/lyx layout

          biblatex

          biber Install the unicode compatible backend processor

          circuit_macros

          script Install cm2pdf to automatically create a correctly sized PDF from a circuit_macro m4 source

          dot2texi

          pgf Enable support for dev-tex/pgf (The TeX Portable Graphic Format)
          pstricks Enable pstricks support

          pythontex

          highlighting Syntax highlighting using dev-python/pygments

          dev-texlive

          texlive-basic

          luajittex Add support for LuaJitTeX: LuaTeX based on LuaJIT which is usually faster.

          dev-util

          android-ndk

          legacy-toolchains Install legacy toolchains
          target-32 Support for 32-bit targets
          target-64 Support for 64-bit targets

          android-studio

          custom-jdk Install and use Android Studio's custom JRE.

          anjuta

          devhelp Enable devhelp integration
          glade Build glade plugin for anjuta
          packagekit 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          terminal Enable terminal plugin based on x11-libs/vte

          apitrace

          cli Enable command line interface
          egl Enable EGL support
          system-snappy Link dynamic against app-arch/snappy

          bazel

          tools Install extra bazel tools to build from sources

          bitcoin-tx

          knots Build enhanced Bitcoin Knots version, rather than Bitcoin Core

          buildbot

          docker Add support for worker docker command steps
          irc Add support for status delivery through an ircbot.
          mail Add support for watching a maildir for commits.
          manhole Add support for manhole (debug over ssh)

          bustle

          interactivetests Build interactive test programs
          threaded Build with support for multithreaded execution.

          catalyst

          ccache Enables ccache support
          iso Pulls in the depends for building iso images
          system-bootloader Pulls in the depends needed to setup livecd bootloader from the host system rather than using a cdtar

          cccc

          apidoc Build software docs with doxygen/graphviz and metrics with cccc
          mfc Add patch for MFC dialect options

          clion

          custom-jdk Install and use IntelliJ's custom JRE.

          cmake

          system-jsoncpp Use system copy of dev-libs/jsoncpp instead of bundled one.

          coccigrep

          vim Install the coccigrep vim plugin

          codeblocks

          contrib Build additional contrib components
          fortran Build FortranProject plugin which enables to use Code::Blocks IDE for Fortran language

          cppcheck

          htmlreport install cppcheck-htmlreport

          ctags

          json Enable JSON output support
          xml Enable XML parsing support
          yaml Enable YAML parsing support

          cutter

          jupyter Add support for jupyter notebook
          webengine Use dev-qt/qtwebengine for in-app jupyter browser

          cwdiff

          a2ps install app-text/a2ps for postscript output
          mercurial install hg wdiff alias for dev-vcs/mercurial

          devhelp

          gedit Install plugin for app-editors/gedit

          dialog

          minimal Disable library, install command-line program only

          diffoscope

          R Use dev-lang/R
          binutils Use sys-devel/binutils
          cpio Use app-arch/cpio
          diff 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          docx Use app-text/docx2txt
          dtc Use sys-apps/dtc
          e2fsprogs Use sys-fs/e2fsprogs
          file Use sys-apps/file
          find Use sys-apps/findutils
          gettext Use sys-devel/gettext
          gpg Use app-crypt/gnupg
          haskell Use dev-lang/ghc
          hex Use app-editors/vim-core
          iso Use virtual/cdrtools
          llvm Use sys-devel/llvm
          opendocument Use app-text/odt2txt
          pascal Use dev-lang/fpc
          rpm Use app-arch/rpm
          squashfs Use sys-fs/squashfs-tools
          ssh Use net-misc/openssh
          tar Use app-arch/tar
          tcpdump Use net-analyzer/tcpdump
          xz Use app-arch/xz-utils
          zip Use app-arch/unzip

          edb-debugger

          jumbo-build Experimental jumbo (also known as unity) build capability

          edi

          clang Provide integration with sys-devel/clang for autocompletion and inline errors

          electron

          gconf Use gnome-base/gconf
          lto Build with link time optimization enabled
          pic Disable optimized assembly code that is not PIC friendly
          proprietary-codecs Enable proprietary codecs like H.264, MP3
          system-ffmpeg Use system ffmpeg instead of the bundled one
          system-libvpx Use system libvpx instead of the bundled one
          system-ssl Use system OpenSSL instead of the bundled one
          tcmalloc Use bundled tcmalloc instead of system malloc

          emilpro

          system-binutils Use the gentoo binutils instead of building against an unpatched vanilla version

          fatrace

          powertop Add powetop integration

          geany

          gtk3 Use GTK+3 instead of GTK+2
          vte Enable Terminal support (x11-libs/vte)

          geany-plugins

          autoclose Enable the autoclose plugin.
          automark Enable the automark plugin
          commander Enable the commander plugin which provides a command panel for rapid access to any action.
          ctags Enable ctags plugin
          debugger Enable the debugger plugin which interfaces with sys-devel/gdb
          defineformat Enable the defineformat plugin.
          enchant Enable spell checking using enchant
          gpg Enable geanypg plugin which integrates GPG using app-crypt/gpgme
          gtk3 Use GTK+3 instead of GTK+2
          gtkspell Use gtkspell for dictionary support in GeanyVC
          markdown Enable the markdown plugin
          multiterm Enable the multiterm plugin
          overview Enable overview plugin
          pretty-printer Enable pretty-printer plugin
          scope Enable the scope plugin which is a graphical GDB front-end
          soup Enable updatechecker and geniuspaste plugins which require net-libs/libsoup
          workbench Enable workbench plugin

          glade

          webkit Build catalog support for net-libs/webkit-gtk:4 widgets.

          global

          vim Integrate the GNU GLOBAL source code tag system with Vim

          gnome-builder

          clang Provide integration with sys-devel/clang for best possible C/C++ autocompletion, semantic highlighting, symbol resolving, and diagnostics support
          devhelp Provide API docs browsing and integration via dev-util/devhelp
          git Provide support for the Git version control system via dev-libs/libgit2-glib (such as setup of Git for New Project, direct cloning for Open Project and changed lines indicators in the editor gutter)
          sysprof Provide an integrated profiler via dev-util/sysprof
          vala Provide an autoindenter, autocompletion, diagnostics, and symbol resolver for Vala
          webkit Enable net-libs/webkit-gtk using plugins support and the HTML/Markdown previewer plugin

          google-perftools

          debug Build a set of libraries with debug support (so-called debugalloc). These are available by default but are not needed unless you're actually developing using tcmalloc.
          largepages Use (experimental) larger pages for tcmalloc, this increases memory usage, but should speed up the allocation/free operations.
          minimal Only build the tcmalloc_minimal library, ignoring the heap checker and the profilers.
          optimisememory To build libtcmalloc with smaller internal caches.

          gtk-doc

          highlight Enable source code highlighting
          vim Enable source code highlighting through app-editors/vim

          heaptrack

          gui Install Qt5-based analyzer tool

          idea-community

          jbr11 Install and use the Java 11 based version of JetBrains Runtime.
          jbr8 Install and use the Java 8 based version of JetBrains Runtime.

          intel-ocl-sdk

          android Install android related files
          system-boost 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          system-clang Use system clang (sys-devel/clang) instead of bundled one
          system-tbb Use system Thread Building Blocks (dev-cpp/tbb) instead of bundled one
          tools Install Intel Offline Compiler

          kdevelop

          gdbui Enable GUI for attaching GDB to a running process
          hex Enable hex editor plugin via app-editors/okteta
          qmake Enable support for QMake build system
          reviewboard Enable reviewboard support
          webkit Enable deprecated dev-qt/qtwebkit instead of dev-qt/qtwebengine for integrated documentation

          kernelshark

          custom-optimization Build with user-specified compiler optimizations (-Os, -O0, -O1, -O2, -O3) from CFLAGS

          ltrace

          unwind Use sys-libs/libunwind for frame unwinding support

          lttng-tools

          ust Support LTTng-UST (Userspace Tracing)

          lttng-ust

          numa Enable numa support

          massif-visualizer

          callgraph Enable detailed snapshot analysis using media-gfx/kgraphviewer

          mdds

          valgrind Add support for memory debugging using dev-util/valgrind

          mingw64-runtime

          idl Install idl files.
          libraries Build extra libraries: mangle, pseh, winpthreads.
          secure-api Expose secure API (*_s function) by default.
          tools Build extra tools: gendef, genidl.

          molecule

          plugins Add plugins provided by dev-util/molecule-plugins

          nemiver

          memoryview Enable the optional hexadecimal memory inspection with app-editors/ghex

          nvidia-cuda-sdk

          cuda Build CUDA binaries
          opencl Build OpenCL binaries

          nvidia-cuda-toolkit

          debugger Installs the CUDA debugger
          eclipse Install plugins for eclipse
          profiler Installs the NVIDIA CUDA visual profiler

          ostree

          archive Use libarchive
          grub Enable grub configuration generator
          libmount Use libmount
          soup Use libsoup for networking

          perf

          clang Enable builtin clang and LLVM support
          demangle Enable C++ symbol name demangling, using libbfd from sys-devel/binutils. When this flag is enabled, the package will have to be rebuilt after every version bump of binutils.
          doc Build documentation and man pages. With this USE flag disabled, the --help parameter for perf and its sub-tools will not be available. This is optional because it depends on a few documentation handling tools that are not always welcome on user systems.
          numa Enable NUMA support
          perl Add support for Perl as a scripting language for perf tools.
          systemtap Add support to define SDT event in perf tools.
          unwind Use sys-libs/libunwind for frame unwinding support.

          pkgcheck

          network Enable support for network checks using dev-python/requests
          perl Enable support for perl checks using dev-perl/沙巴体育-PerlMod-Version

          pkgconf

          pkg-config Install as a replacement for dev-util/pkgconfig

          pkgconfig

          internal-glib Use internal copy of dev-libs/glib

          scanmem

          gui Enable the GameConqueror GUI

          sccache

          azure Enable Azure Blob Storage support
          dist-client Enables distributed support in the sccache client
          dist-server Enables the sccache-dist binary
          gcs Enable Google Cloud Storage support
          redis Enable Redis support
          s3 Enable Amazon S3 support

          schroot

          btrfs Enable support for chroots using btrfs snapshots
          dchroot Enables the building of a wrapper named "dchroot", replacing sys-apps/dchroot
          lvm Enable support for chroots using LVM snapshots

          spirv-llvm-translator

          tools Install the command-line translator llvm-spirv

          strace

          aio Enable dev-libs/libaio support for tracing Asynchronous I/O operations
          elfutils Enable stack backtraces (-k flag) via dev-libs/elfutils
          unwind Enable stack backtraces (-k flag) via sys-libs/libunwind

          suse-build

          symlink Provide compatibility symlinks with original openSUSE package (might clash with other packages)

          sysdig

          modules Build kernel modules needed for tracing local events. Disable this only if you intend to use sysdig purely to work with dumpfiles.

          sysprof

          elogind Build the sysprofd daemon service, required to run the UI without root permissions. Relies on sys-auth/elogind for sd-bus API.
          systemd Build the sysprofd daemon service, required to run the UI without root permissions. Relies on sys-apps/systemd for sd-bus API.

          systemtap

          libvirt Support probing of libvirt domains.

          trace-cmd

          udis86 Enable support for dev-libs/udis86 disassembler library

          uftrace

          capstone Use capstone to provide dynamic tracing without recompilation

          vulkan-tools

          cube Build the cube/cubepp demos
          vulkaninfo Build the vulkaninfo utility

          dev-vcs

          bzr

          sftp Enable sftp support

          cssc

          valgrind Enable usage of dev-util/valgrind in tests

          cvs

          server Enable server support

          cvs2svn

          bazaar Support for dev-vcs/bzr

          cvsync

          gcrypt Use dev-libs/libgcrypt for hash functions.
          mhash Use app-crypt/mhash for hash functions.
          openssl Use dev-libs/openssl for hash functions.

          darcs

          diff Use 'lcs' for diff building.
          http Use the pure Haskell HTTP package for HTTP support.
          network-uri Get Network.URI from the network-uri package.
          terminfo Use the terminfo package for enhanced console support.
          threaded Use threading and SMP support.

          fossil

          fusefs Enable the Fuse Filesystem
          json Enable the JSON API of Fossil's wiki
          legacy-mv-rm Enable legacy behavior for mv/rm (skip checkout files).
          miniz Use the bundled miniz for compression instead of zlib. Incompatible with ssl.
          system-sqlite Use the system SQLite instead of the bundled one
          tcl-private-stubs Enable Tcl integration via private stubs mechanism
          tcl-stubs Enable Tcl integration via stubs library mechanism
          th1-docs Enable TH1 for embedded documentation pages
          th1-hooks Enable TH1 hooks for commands and web pages

          git

          blksha1 Use the new optimized SHA1 implementation
          cgi Install gitweb too
          curl Support fetching and pushing (requires webdav too) over // and // protocols
          gpg Pull in gnupg for signing -- without gnupg, attempts at signing will fail at runtime!
          highlight GitWeb support for app-text/highlight
          mediawiki Support pulling and pushing from MediaWiki
          mediawiki-experimental Add experimental patches for improved MediaWiki support
          pcre-jit Enable JIT for pcre
          perforce Add support for Perforce version control system (requires manual installation of Perforce client)
          ppcsha1 Make use of a bundled routine that is optimized for the PPC arch
          subversion Include git-svn for dev-vcs/subversion support
          tk Include the 'gitk' and 'git gui' tools
          webdav Adds support for push'ing to HTTP/HTTPS repositories via DAV

          git-annex

          assistant Enable git-annex assistant and watch command
          benchmark Enable benchmarking
          concurrentoutput Use concurrent-output library (experimental)
          magicmime Use libmagic to determine file MIME types
          network-uri Get Network.URI from the network-uri package.
          pairing Enable pairing of git annex repositories
          s3 Enable Amazon S3 remote
          torrentparser Use haskell torrent library to parse torrent files
          webapp Enable git-annex webapp
          webdav Enable webdav remote

          gitg

          glade Install a glade catalog file
          python Install Python bindings for those plugins requiring it.

          gitolite

          contrib Install user-contributed files
          tools Install tools to e.g. convert a Gitosis config to gitolite or one to check if your setup is gitolite >= 3.x compatible

          gitolite-gentoo

          contrib Install user-contributed files
          tools Install tools to e.g. convert a Gitosis config to gitolite or one to check if your setup is gitolite >= 3.x compatible

          kdesvn

          man Build and install man pages

          mercurial

          bugzilla Support bugzilla integration.
          chg Support Mercurial command server client
          gpg Support signing with GnuPG.
          tk Install dev-lang/tk for hgk script.

          rabbitvcs

          caja Enable extension for mate-base/caja
          cli Eanble console based frontend
          diff Use for diff command dev-util/meld
          gedit Enable plugin for app-editors/gedit
          nautilus Enable extension for gnome-base/nautilus
          thunar Enable extension for xfce-base/thunar

          subversion

          ctypes-python Build and install Ctypes Python bindings
          dso Enable runtime module search
          extras Install extra scripts (examples, tools, hooks)
          http Enable http support using net-libs/serf
          kwallet Enable encrypted storage of passwords with kde-frameworks/kwallet

          games-action

          beathazardultra

          bundled-libs Use the upstream provided bundled libraries.

          chromium-bsu

          mixer Enables media-libs/sdl-mixer sound backend instead of media-libs/openal one.

          d1x-rebirth

          demo Use the demo data instead of the full game
          l10n_de Provides German translations for the game's briefings, robot descriptions, and outro of the original campaign
          music Support for ingame music
          opl3-musicpack Include alternate version of the game's music, recorded with the Yamaha YMF262 OPL3 soundchip
          sc55-musicpack Include alternate version of the game's music, recorded with the Roland Sound Canvas SC-55 MIDI module

          dxx-rebirth

          data Install data files
          descent1 Install Descent 1 resources and executable
          descent2 Install Descent 2 resources and executable
          l10n_de Provides German translations for the game's briefings, robot descriptions, and outro of the original campaign
          music Enable music support
          opl3-musicpack Include alternate version of the game's music, recorded with the Yamaha YMF262 OPL3 soundchip
          sc55-musicpack Include alternate version of the game's music, recorded with the Roland Sound Canvas SC-55 MIDI module
          textures Include high resolution (640x480) backgrounds, briefing images and fonts (Descent 1)

          hotline-miami

          bundled-libs Use bundled libraries.
          launcher Install qt launcher

          minetest

          client Build Minetest client
          leveldb Enable LevelDB backend
          redis Enable redis backend via dev-libs/hiredis
          server Build Minetest server
          spatial Enable SpatialIndex AreaStore backend

          solar2

          bundled-libs Use the upstream provided bundled libraries.

          supermariowar

          server Compile and install Super Mario War server files

          supertuxkart

          fribidi Support for right-to-left languages
          nettle Use dev-libs/nettle crypto backend
          recorder Enable recording with media-libs/libopenglrecorder
          wiimote Support for wiimote input devices

          swordandsworcery

          bundled-libs Use the upstream provided bundled libraries.

          trine

          launcher Install GTK+ launcher

          trine-enchanted-edition

          launcher Install GTK+ launcher

          trine2

          launcher Install GTK+ launcher

          games-arcade

          bomns

          editor enables building the level editor

          burgerspace

          network Enable client-server support

          commandergenius

          downloader Allows some Keen games to be downloaded from the menu

          jumpnbump

          music Enable playing of background music

          lbreakout2

          themes Install additional themes

          moleinvasion

          music Download and install the music files

          oshu

          osu-skin Include more complete osu-skin (other is minimal)

          performous

          midi Enable MIDI I/O support
          songs Install a few demo songs
          tools Enable building of song extraction utilities for SingStar and Guitar Hero
          webcam Enable Webcam support

          savagewheels

          fmod Enable the fmod music and sound effects library

          tuxanci

          physfs Use dev-games/physfs instead of dev-libs/libzip to load compressed data

          games-board

          cockatrice

          client Build with client
          oracle Build with oracle
          server Compile server support

          crafty

          no-opts Don't try to enable crazy CFLAG options

          freedoko

          backgrounds Install additional background images
          gnomecards Install the gnome-games card set
          kdecards Install the KDE card set
          net Enable network game support
          openclipartcards Install the openclipartcards card set
          pysolcards Install the PySol card set
          xskatcards Install the XSkat card set

          grhino

          gtp Install the GTP (Go/Game Text Protocol) frontend

          pasang-emas

          extras Install some extra themes

          pioneers

          help Enable gnome ingame help via scrollkeeper

          pysolfc

          extra-cardsets Install extra cardsets
          sound Enable sound support using dev-python/pygame

          spider

          athena Enable athena widgets

          stockfish

          armv7 Build for armv7; enables PIE
          general-32 Generic unoptimized 32-bits build
          general-64 Generic unoptimized 64-bits build
          optimize Enable upstream -O3 optimizations (default enabled)

          tablebase-syzygy

          6-pieces Install tablebases for 6 pieces (huge!)

          teg

          client Compile the client
          debug Turn on debugging
          ggz Enable GGZ Gaming Zone support
          robot Compile the robot
          server Compile the server

          xboard

          default-font Install the default font that xboard uses
          zippy Enable experimental zippy client

          games-emulation

          dolphin

          discord-presence Enables Discord Rich Presence, show the current game on Discord
          egl Enable EGL support
          evdev Enable evdev input support
          log Increase logging output
          lto Add support for link-time optimizations.

          dosbox

          core-inline Enable memory-increasing inlines for better performance but requiring more build time
          glide Enable unofficial Glide emulation via media-libs/openglide

          fceux

          logo Enable the ability to add a logo screen when creating AVIs

          generator

          sdlaudio Enable SDL Audio

          hatari

          capsimage Use dev-libs/spsdeclib to read .IPF, .RAW, and .CTR disk images
          microphone Use media-libs/portaudio for Falcon microphone handling
          portmidi Use media-libs/portmidi as an alternative MIDI backend
          sdl2 Use libsdl2 instead of libsdl

          higan

          icarus Build icarus library manager
          udev Enable udev based input

          m64py

          7z Ensure support for .7z archives.
          rar Ensure support for .rar archives.

          mednafen

          debugger Build with internal debugger

          mgba

          elf Enable the use of elf utils via dev-libs/elfutils

          mupen64plus

          audio-sdl Enable SDL audio plugin.
          input-sdl Enable SDL input plugin.
          rsp-hle Enable HLE RSP plugin.
          ui-console Enable default console UI.
          ui-m64py Enable PyQt5 UI using games-emulation/m64py.
          video-glide64mk2 Enable Glide64mk2 video plugin.
          video-rice Enable Rice video plugin.

          mupen64plus-core

          debugger Build the debugger
          gles2 Use GLES2 instead of OpenGL
          new-dynarec Enable new experimental dynamic recompiler implementation (only for x86 and arm)
          opencv Support video capture via media-libs/opencv
          osd Overlay emulator messages using on-screen-display

          mupen64plus-video-glide64mk2

          gles2 Use GLES2 instead of OpenGL
          hires Support hi-resolution textures (requires dev-libs/boost)

          mupen64plus-video-rice

          gles2 Use GLES2 instead of OpenGL

          nestopia

          gui Enable GUI

          pcsxr

          cdio Use libcdio for CD support
          sdl Use SDL sound backend (other parts of SDL are used unconditionally)

          ppsspp

          headless Build headless version of the PPSSPP
          system-ffmpeg Use the system-wide media-video/ffmpeg instead of bundled

          snes9x

          netplay Enable playing ROMs over the network (not recommended)

          vbam

          link Enable GBA linking functionality

          zsnes

          debug Enable the builtin debugger

          games-engines

          exult

          sdl2 Use libsdl2 instead of libsdl

          frobtads

          tads2compiler Build TADS2 compiler
          tads3compiler Build TADS3 compiler

          odamex

          client Build client target
          master Build master server target (advertises odamex server list)
          odalaunch Build the wxWidgets based launcher
          portmidi Enable PortMidi support
          server Build server target

          openmw

          devtools Install development tools like bsatool, esmtool and opencs.

          renpy

          development Install IDE for game developers and an empty game template

          residualvm

          mpeg2 enable mpeg2 codec for cutscenes

          scummvm

          fluidsynth compile with support for fluidsynth
          mpeg2 enable mpeg2 codec for cutscenes
          net enable cloud support via media-libs/sdl2-net
          speech enable text-to-speech support through app-accessibility/speech-dispatcher
          unsupported enable unsupported and/or broken game engines (you're on your own)

          solarus

          doc Install doxygen developer documentation.

          stratagus

          fluidsynth compile with support for fluidsynth

          games-fps

          alienarena

          vidmode Link against x11-libs/libXxf86vm. Required for full-screen support.

          darkplaces

          cdsound Enables using CD audio in the engine
          demo Uses the demo data from quake1 (quake1-demodata)
          lights Install and setup the updated light maps
          textures Install and setup the updated textures

          doomsday

          demo Install launcher dor doom1.wad from games-fps/doom-data
          fluidsynth Build the FluidSynth sound driver
          fmod Enable support for fmod music and sound effects lib
          freedoom Install launcher for doom1.wad from games-fps/freedoom
          tools Build additional tools such as doomsday-shell, md2tool and texc

          duke3d-data

          gog Extract the data from the GOG.com installer.

          eduke32

          demo Install the Duke Nukem 3D demo files, provided by games-fps/duke3d-demodata.
          fluidsynth Install media-libs/sdl2-mixer with fluidsynth support.
          hrp Install the Duke Nukem 3D High Resolution Pack.
          offensive Install the Duke Nukem 3D XXX Pack.
          opl Install the Duke Nukem 3D OPL music files.
          psx Install the Duke Nukem 3D PSX high resolution voice files.
          sc-55 Install the Duke Nukem 3D Roland SC-55 music files.
          sdk Install the SDK files.
          server Enable support for multiplayer.
          tools Install the support tools for mapster32.
          voxels Install the Duke Nukem 3D Voxels Pack.
          vpx Enable support for media-libs/libvpx.
          xmp Enable support for media-libs/exempi.

          gzdoom

          gtk2 Enable support for GTK+2 instead of GTK+3
          nonfree Enable non-free components

          nexuiz

          maps Install the community map pack

          prboom-plus

          dumb Enable support for various tracker-style music formats via media-libs/dumb
          fluidsynth Enable support for MIDI via media-sound/fluidsynth
          net Enable support for network play
          nonfree Enable non-free components
          portmidi Enable support for MIDI via media-libs/portmidi
          sdl-image Enable support for high-resolution texture support via media-libs/sdl-image
          sdl-mixer Enable support for MIDI via media-libs/sdl-mixer

          quake2-icculus

          demo Install the demo files (quake2-demodata) and configure for use
          qmax Build the pretty version (quake max)
          rogue Build support for the 'Ground Zero' Mission Pack (rogue)
          xatrix Build support for the 'The Reckoning' Mission Pack (xatrix)

          quakeforge

          wildmidi enable libWildMidi support
          xdg enable XDG support

          qudos

          demo Install the demo files (quake2-demodata) and configure for use
          mods Build support for the quake2 mission packs
          qmax Build the pretty version (quake max)
          textures Install the enhanced textures (quake2-textures)

          redeclipse

          dedicated Install only as a dedicated game server

          rott

          demo Install the shareware version

          sauerbraten

          server Compile server support

          turtlearena

          mumble Adds player-location (positional audio) support to VoIP
          server Build server target
          voice Adds VoIP support

          urbanterror

          altgamma Alternative way for gamma setting with modesetting driver
          client Build binary for client (includes code for non-dedicated server)
          mumble Use Mumble for ingame VoIP (experimental)
          server Build binary for dedicated server
          skeetshootmod Build support for skeetshoot mod for specific maps
          voip Use ioq3 ingame VoIP (experimental)

          worldofpadman

          maps Install extra maps (PadPack)

          xonotic

          ode Enable support for physics engine from dev-games/ode

          yamagi-quake2

          client Build client
          ctf Build support for the 'Capture The Flag' addon
          rogue Build support for the 'Ground Zero' Mission Pack
          softrender Build software renderer
          xatrix Build support for the 'The Reckoning' Mission Pack

          games-kids

          gcompris

          kiosk Enable kiosk mode by default (for use by small children or on a self-service host machine)

          tuxtype

          pango Render fonts using media-libs/sdl-pango instead of media-libs/sdl-ttf

          games-misc

          little-inferno

          bundled-libs Use bundled libraries.

          ponysay

          fish-completion Enable fish completion support
          non-free Install non-free ponies (i.e. from the MLP franchise)

          xcowsay

          fortune Enable support for fortune cookies via games-misc/fortune-mod

          games-mud

          tf

          atcp enable ATCP support.
          gmcp enable GMCP support.
          option102 enable telnet option 102 support.

          games-puzzle

          cuyo

          music Enable playing of background music

          nightsky

          bundled-libs Use the upstream provided bundled libraries.

          numptyphysics

          user-levels Install some fun user-created levels

          pingus

          music Enable playing of background music

          sgt-puzzles

          gtk3 Use x11-libs/gtk+:3 instead of x11-libs/gtk+:2

          tiny-and-big

          bundled-libs Use the upstream provided bundled libraries.

          xlogical

          alt_gfx Use alternate graphics which are closer to the original Amiga version

          games-roguelike

          FTL

          bundled-libs Use bundled libraries.

          angband

          sdl2 Use libsdl2 instead of libsdl
          sound Enable and install sounds

          nethack

          experimental Enable experimental features (showscore and status_hilite)

          stone-soup

          ncurses Enable for console (uses ncurses) based build. (can be enabled on top of tiles)
          tiles Enable for graphical (tiled) build. (can be enabled on top of ncurses)

          tomenet

          server Compile server support

          games-rpg

          arx-fatalis-data

          gog Extract the data from the GOG.com installer.

          arx-libertatis

          c++0x Build ROOT using the C++11 standard.
          crash-reporter Build a dev-qt/qtgui-based tool that allows to submit crash information to the upstream backtracker.
          debug Enable asserts and debug logging.
          static Link libraries statically, currently only media-libs/glew
          tools Build tools that can extract the game's data and save files.
          unity-build Build everything in one big source file, allowing for faster build times and better optimizations at the cost of higher memory usage.

          daimonin-client

          music Install extra music

          drascula

          sound Install optional audio files

          dreamweb

          doc High-resolution scans of the written material in the original UK game box

          dungeon-defenders

          bundled-libs Use the upstream provided bundled libraries.

          freedroidrpg

          devtools Compile the additional dev tools
          profile Enable the integration of the ingame real-time profiler
          sanitize Compile with address sanitizer

          hatoful-boyfriend

          gui Install the GUI for configuring screen resolution and input

          hatoful-boyfriend-holiday-star

          gui Install the GUI for configuring screen resolution and input

          kqlives

          cheats Enable cheating mode

          manaplus

          mumble Enable support for voice chat
          pugixml Use dev-libs/pugixml for XML parsing isntead of dev-libs/libxml2
          sdl2 Use libsdl2 instead of libsdl

          sumwars

          tools Builds editor tools

          to-the-moon

          bundled-libs Use bundled libraries

          games-simulation

          corsix-th

          midi Adds support for background MIDI music via SDL_mixer

          flightgear

          dbus Enable screensaver DBus interaction
          gdal Enable alternative terrain engine based on pagedLOD using sci-libs/gdal
          qt5 Build Qt5 launcher application
          udev Enable event-based Input devices through virtual/udev
          utils Build various utilities (fgpanel, fgviewer among others)

          openrct2

          lightfx Enables LightFX for better lightning effects.
          twitch Enables streaming of ingame content to Twitch.

          openttd

          aplaymidi Enables midi music in game, using aplaymidi as an external player
          dedicated Build only the openttd server, and not the client.
          lzo Enables LZO compression for savegames. This is only needed to load extremely old savegames. (versions before 0.2)
          openmedia Enables the free open media sets: OpenGFX, OpenSFX, OpenMSX, removing the requirement for proprietary TTD assets to play OpenTTD.

          singularity

          music Install music files

          train-valley

          gui Install the GUI for configuring screen resolution and input

          games-sports

          speed-dreams

          xrandr Enable support for the X xrandr extension

          xmoto

          double-precision more precise calculations at the expense of speed
          editor Depend on inkscape, scripts to convert svg to level (svg2lvl)

          500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          0ad

          editor Include Atlas scenario editor projects
          lobby Enable the use of net-libs/gloox and the multiplayer lobby
          nvtt Support for some uncompressed data formats via media-gfx/nvidia-texture-tools (might be needed for some mods)

          colobot

          devbuild TODO
          tools Build tools

          colobot-data

          music Enable music support
          music-flac-convert Fetch flac music and convert it to ogg
          music-ogg Fetch ogg music

          defcon-demo

          system-libs Use system libraries instead of the ones included in the upstream distribution.

          freeciv

          aimodules Support for dynamically loadable AI modules (server-side)
          auth Add authentication capability via mysql, postgres or sqlite3
          mapimg 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          modpack Build the freeciv-modpack-program to download/install mods
          server Enable server support. Disabling this will also make it impossible to start local games.
          sound Add support for sound provided by media-libs/sdl-mixer
          system-lua Use dev-lang/lua instead of the bundled liblua

          freesynd

          devtools Build development tools

          hedgewars

          server Enable local server

          ja2-stracciatella

          editor Adds necessary file to run the editor
          ru-gold Support for russian gold ja2 version

          megaglest

          editor Build map editor
          fribidi Enable FriBIDi support
          model-viewer Build model viewer
          streflop Use the library streflop. Out of synchs may occur if not enabled.
          tools Build model import/export tools
          unicode Use unicode strings for wxwidgets
          wxuniversal Use the wxUniversal port which implements the various GUI controls by drawing them itself

          naev

          mixer Enables media-libs/sdl-mixer sound backend in addition to media-libs/openal one.

          satellite-reign

          gui Install the GUI for configuring screen resolution and input

          ufoai

          client Build the main game client
          editor Build the map editor and compiler
          server Build the dedicated server

          uqm

          music download and install music files (large)
          remix download and install music remix files (large)
          voice download and install voice files (large)

          wesnoth

          fribidi Support for right-to-left languages
          server Enable compilation of server

          games-util

          deutex

          man Build and install man pages

          gslist

          web Enable the web interface

          lgogdownloader

          gui Enable GUI login support for passing reCAPTCHA

          pyfa

          graph Enable support for graphs

          wit

          fuse Enable image mount support via fuse

          gnome-base

          gconf

          ldap Build backend which enables default mail accounts, addressbooks and calendars for Evolution to be configured using each user's LDAP entry."

          gdm

          bluetooth-sound Allow loading of bluetooth sound modules. This may be necessary for accessibility screen readers, but may cause bluetooth sound issues for users logging in.
          elogind Use sys-auth/elogind for session management
          fprint Enables experimental fingerprint authentication using sys-auth/fprintd
          plymouth Enable support for smooth transition from sys-boot/plymouth

          gnome

          classic Install gnome-extra/gnome-shell-extensions for the Gnome Shell Classic mode
          extras Install additional GNOME applications

          gnome-applets

          tracker Build the tracker search bar applet

          gnome-control-center

          flickr Add support for using photos from flickr as desktop background
          gnome-online-accounts Enable configuration panel for net-libs/gnome-online-accounts accounts
          ibus Enable support for enhanced input methods through app-i18n/ibus

          gnome-desktop

          license-docs Install help files documenting GNOME's licenses

          gnome-extra-apps

          games Install Gnome Games
          share Install the gnome-extra/gnome-user-share personal file sharing tool
          shotwell Install the media-gfx/shotwell photo manager
          tracker Install the app-misc/tracker indexer and the GNOME packages that require it

          gnome-keyring

          ssh-agent Use GNOME Keyring to unlock SSH keys. Recommended unless you are using ECDSA or Ed25519 keys.

          gnome-light

          gnome-shell Install gnome-base/gnome-shell and x11-wm/mutter for the standard GNOME 3 desktop mode

          gnome-session

          consolekit Support sys-auth/consolekit for session tracking
          elogind 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          gnome-settings-daemon

          elogind Rely on sys-auth/elogind as runtime logind provider
          systemd Rely on sys-apps/systemd as runtime logind provider

          gnome-shell

          browser-extension Ensure the presence of extensions.gnome.org native connector gnome-extra/chrome-gnome-shell
          elogind Use sys-auth/elogind for session tracking and suspend support.
          ibus Enable support for enhanced input methods through app-i18n/ibus
          telepathy Ensure presence of telepathy chat integration

          gvfs

          afp Enables support for accessing AFP (Apple Filing Protocol) network shares
          archive Enables support for accessing files in archives transparently via app-arch/libarchive
          bluray Enable playback of Blu-ray filesystems using media-libs/libbluray
          elogind Use sys-auth/elogind for session tracking.
          fuse Enables fuse mount points in $HOME/.gvfs for legacy application access
          gnome-online-accounts Enable configuration panel for net-libs/gnome-online-accounts accounts
          google Enables support for accessing Google accounts via dev-libs/libgdata
          http Enable the HTTP/DAV backend using net-libs/libsoup
          nfs Enable NFS client support via net-fs/libnfs.
          udev Enable udev base replacement code for cdda feature

          libglade

          tools Install libglade-convert Python script.

          libgnomecanvas

          glade Enable glade support

          librsvg

          tools Build svg viewer tool

          nautilus

          gstreamer Enable the Audio/Video file properties page
          packagekit Use packagekit to search for programs to open unknown file types
          previewer Use gnome-extra/sushi to preview files from the file mananger
          sendto Enable the nautilus-sendto extension to send files to various locations/devices

          orbit

          pic Force libname-server-2 to be built as PIC; needed on hardened systems

          gnome-extra

          cinnamon-session

          elogind Rely on sys-auth/elogind as runtime logind provider

          eiciel

          nautilus Build gnome-base/nautilus extension

          evolution-data-server

          berkdb sys-libs/db support needed to migrate old (pre-3.13 evolution versions) addressbook data
          gnome-online-accounts Enable net-libs/gnome-online-accounts based Google authentication support
          oauth Enable internal OAuth2 authentication support for Google and Outlook.com. If gnome-online-accounts is enabled and used, this is not necessary, but both can be supported at the same time with different setup at runtime
          weather Enable optional weather calendar support

          gnome-color-manager

          packagekit Enable support for the distro-neutral package manager GUI app-admin/packagekit

          gnome-commander

          chm Enable metadata support for Microsoft Compiled HTML Help files
          gsf Add metadata support for OLE, OLE2 and ODF
          pdf Add metadata support for PDF
          taglib Add metadata support for ID3, Vorbis, FLAC and APE
          unique Enable single instance support using dev-libs/libunique

          gnome-contacts

          telepathy Start chat from contact details

          gnome-dvb-daemon

          totem Build a plugin for media-video/totem

          gnome-shell-extension-gsconnect

          nautilus Install Nautilus extension for sending files via GSConnect

          gnome-software

          firmware Enable firmware update support through sys-apps/fwupd
          packagekit Enable module for package manager integration

          gnome-system-monitor

          systemd Display sys-apps/systemd metadata, e.g. unit names, for running processes

          libgda

          canvas Enable support for x11-libs/goocanvas
          http Enable embedded net-libs/libsoup based server
          json Enable support for JSON format
          mdb Enable support for Microsoft Access database using app-office/mdbtools
          reports Install tools for generating graphical reports
          sourceview Enable support for x11-libs/gtksourceview

          libgsf

          gtk Enable use of gdk in thumbnailer

          nemo

          packagekit Use packagekit to search for programs to open unknown file types
          tracker Add support for app-misc/tracker search

          nm-applet

          gcr Enable advanced certificate chooser, requires app-crypt/gcr
          modemmanager Enable support for mobile broadband devices using net-misc/modemmanager
          teamd Enable teamd configuration editor

          sushi

          office Support viewing file formats such as generated by app-office/libreoffice

          synapse

          indicator Build support for application indicators using dev-libs/libappindicator
          plugins Build support for plugins using net-libs/rest

          gnustep-apps

          gemas

          projectcenter Build and install plugin for gnustep-apps/projectcenter

          gworkspace

          gwmetadata Enable the metadata indexing and searching system

          sogo

          activesync Build the ActiveSync support code

          gnustep-base

          gnustep-back-art

          xim Enable X11 XiM input method

          gnustep-back-cairo

          xim Enable X11 XiM input method

          gnustep-back-xlib

          xim Enable X11 XiM input method

          gnustep-gui

          speech Audio support using app-accessibility/flite

          gnustep-make

          libobjc2 Enables use of the GNUstep Objective-C runtime (gnustep-base/libobjc2) with non-fragile ABI and sys-devel/clang compiler
          native-exceptions 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          libobjc2

          boehm-gc Enable Hans Boehm's garbage collector (dev-libs/boehm-gc). Not recommended by upstream

          gui-apps

          grim

          jpeg Enable JPEG support.
          man Generate and install man pages.

          mako

          icons Enable support for icons

          slurp

          man Generate and install man pages.

          swaybg

          man Build and install man pages

          swayidle

          elogind Enable support for rootless session via elogind
          fish-completion Enable fish completion support
          man Build and install man pages

          swaylock

          fish-completion Enable fish completion support
          gdk-pixbuf Enable additional image format support via the x11-libs/gdk-pixbuf library
          man Build and install man pages

          waybar

          mpd Enable support for the Music Player Daemon
          network Enable libnl support for network related features
          tray Enable support for tray

          gui-libs

          libhandy

          glade Install module and catalog for dev-util/glade

          wlroots

          X Enable support for X11 applications (XWayland)
          elogind Enable support for rootless session via elogind
          icccm Use xcb-icccm (from x11-libs/xcb-util-wm) util library for improved Xwayland introspection
          x11-backend Enable support for handling input/output devices through x11-libs/libxcb

          gui-wm

          sway

          X Enable support for X11 applications (XWayland)
          elogind Enable support for rootless session via elogind
          fish-completion Enable fish completion support
          man Build and install man pages
          swaybar Install 'swaybar': sway's status bar component
          swaybg Install 'swaybg': allows to set a desktop background image
          swayidle Install 'swayidle': idle manager to run commands when user is inactive
          swaylock Install 'swaylock': sway's screen locker
          swaymsg 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          swaynag Install 'swaynag': shows a message with buttons
          tray Enable support for StatusNotifierItem tray specification
          wallpapers Install sway's default wallpaper image

          kde-apps

          akonadi

          designer Install plugin for dev-qt/designer
          kaccounts Enable support for system-wide defined KAccounts
          tools Install tools for developers and testing

          analitza

          eigen Enable dev-cpp/eigen mathematical templates support

          ark

          zip Enable ZIP archive support via dev-libs/libzip

          artikulate

          qtmedia Enable playback via Qt5Multimedia

          cantor

          R Enable dev-lang/R backend support
          analitza Enable kde-apps/analitza backend support
          julia Enable dev-lang/julia backend support
          markdown Enable Markdown support via app-text/discount
          qalculate Enable sci-libs/libqalculate backend support

          dolphin

          activities Track which folders are frequently accessed on a Plasma desktop

          gwenview

          activities Enable kactivities support
          fits Enable support for NASA's sci-libs/cfitsio library
          kipi Enable support for the KDE Image Plugin Interface
          mpris Enable support for MPRIS2 interface, requiring dev-qt/qtdbus as dependency.
          share Enable support for a share menu using kde-frameworks/purpose

          k3b

          emovix Enable burning support for eMoviX images

          kalzium

          editor Enable the embedded molecule editor/viewer
          solver Enable the equation solver

          kanagram

          speech Enable text-to-speech support

          kate

          activities Enable Plasma Activities support via kde-frameworks/kactivities
          addons Build and install additional plugins
          filebrowser Enable File System browser tool view
          lspclient Enable LSP (Language Server Protocol) client plugin
          plasma Enable Session Applet addon for KDE Plasma
          projects Enable Project plugin for executing queries on SQL DBs
          snippets Enable Snippets Tool View plugin to manage or download code snippets
          sql Enable SQL plugin for executing queries on SQL DBs

          kde-apps-meta

          pim Pull in KDE PIM suite
          sdk 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          kdeadmin-meta

          cron Installs KDE application for virtual/cron configuration

          kdecore-meta

          share Install kde-frameworks/purpose for share file context menu actions in kde-apps/dolphin
          thumbnail Install kde-apps/ffmpegthumbs and kde-apps/thumbnailers for thumbnail generation in kde-apps/dolphin
          webengine Enable www-client/falkon which depends on dev-qt/qtwebengine
          webkit Enable kde-apps/konqueror with kde-misc/kwebkitpart which depend on dev-qt/qtwebkit

          kdeedu-meta

          webengine Enable kde-apps/kalzium and kde-apps/parley, requiring dev-qt/qtwebengine

          kdegraphics-mobipocket

          thumbnail Enables thumbnail generation

          kdemultimedia-meta

          cdrom Include packages for optical discs

          kdenetwork-meta

          dropbox Enable support for Dropbox in kde-apps/dolphin via kde-apps/dolphin-plugins-dropbox
          telepathy Enable support for Plasma Telepathy (instant messaging) integration via kde-apps/plasma-telepathy-meta

          kdenlive

          freesound Enable freesound.org credentials support via dev-qt/qtwebkit to download files
          gles2 Use GLES 2.0 or later instead of full OpenGL
          share Enable support for a share menu using kde-frameworks/purpose

          kdepim-addons

          importwizard Enable additional import plugins for kde-apps/akonadi-import-wizard
          markdown Enable Markdown support via app-text/discount

          kdepim-meta

          bogofilter Install mail-filter/bogofilter for spam filter support in kde-apps/kmail
          clamav Install app-antivirus/clamav for virus detection support in kde-apps/kmail
          spamassassin Install mail-filter/spamassassin for spam filter support in kde-apps/kmail

          kdesdk-meta

          bazaar Enable support for Bazaar VCS in kde-apps/dolphin via kde-apps/dolphin-plugins-bazaar
          git Enable support for Git VCS in kde-apps/dolphin via kde-apps/dolphin-plugins-git
          mercurial Enable support for Mercurial VCS in kde-apps/dolphin via kde-apps/dolphin-plugins-mercurial
          subversion Enable support for Apache Subversion VCS in kde-apps/dolphin via kde-apps/dolphin-plugins-subversion

          kdeutils-meta

          7zip Install app-arch/p7zip for 7zip archive support in kde-apps/ark
          floppy Install kde-apps/kfloppy to format and create DOS or ext2fs filesystems in a floppy.
          gpg Install kde-apps/kgpg which depends on kde-apps/akonadi
          lrz Install app-arch/lrzip for LRZ archive support in kde-apps/ark
          rar Install one of app-arch/rar, app-arch/unrar or app-arch/unar for RAR archive support in kde-apps/ark
          webengine Enable kde-apps/kimagemapeditor, requiring dev-qt/qtwebengine

          keditbookmarks

          man Build and install man pages

          kget

          bittorrent Enable bittorrent transfer plugin through net-libs/libktorrent
          gpg Enable signature verification by GpgME++ via app-crypt/gpgme
          mms Enable MMS (Microsoft Media Server) plugin through media-libs/libmms

          kig

          geogebra Support files created by sci-mathematics/geogebra
          scripting Support Python scripting

          kio-extras

          activities Enable activities kioslave and fileitem plugin
          man Enable manpages kioslave
          phonon Enable file audio preview plugin using media-libs/phonon
          sftp Enable SFTP protocol support using net-libs/libssh
          taglib Enable audio thumbnails via media-libs/taglib

          kipi-plugins

          flashexport Build the flash export plugin
          mediawiki Build the mediawiki export plugin
          remotestorage Build plugin for remote storage using network protocols such as FTP, SSH, SAMBA via kde-frameworks/kio
          vkontakte Build plugin for vkontakte.ru

          kitinerary

          barcode Enable support for PDF417 and Aztec barcode decoding using media-libs/zxing-cpp

          kmag

          keyboardfocus Enable keyboard focus tracking

          knights

          speech Enable text-to-speech support

          konqueror

          activities Enable kactivities support
          speech Build text-to-speech plugin
          webengine Enable dev-qt/qtwebengine as web browser engine (fallback is kde-misc/kwebkitpart)

          kopete

          addbookmarks Automatically add incoming urls to bookmarks.
          autoreplace Automatically replace selected text
          contactnotes Enables writing personal notes for contacts.
          gadu Enable the Gadu protocol handler.
          groupwise Enable the Groupwise protocol handler.
          highlight Allows you to specify highlights on specific events.
          history Enables saving chat history.
          latex Embed latex formatted text into messages.
          meanwhile Enable the Sametime protocol handler.
          nowlistening Shows song you currently listen to in your status/etc. Bindings for many players.
          oscar Enable Oscar (AIM/ICQ) IM protocol support
          otr Allows crypting your chat (drugs and talking nonsense are considered as good alternatives ;]).
          pipes Send messages to external pipe.
          privacy Filter for incoming messages
          statistics Everybody loves statistic graphs, especially cake ones. ;]
          testbed Enable the testbed protocol.
          texteffect Various fancy text effects for your messages (don't ever consider writing us with this enabled ;]).
          translator Translate incoming and outgoing messages.
          urlpicpreview Enables in conversation pictures preview.
          webpresence Show your status and some more information on web.
          winpopup Enable pop-up messages sending on windows. (same as good old "net send" messages ;])
          zeroconf Enable Link-Local Messaging via the bonjour protocol.

          kpimtextedit

          designer Build plugins for dev-qt/designer

          ktp-accounts-kcm

          experimental Enables disabled telepathy services (currently only steam)

          ktp-common-internals

          otr Enable support for encrypted conversations using Off-The-Records messaging
          sso Enable support for Single sign-on through KAccounts

          ktp-text-ui

          speech Enable incoming messages to be read out using text-to-speech

          kwave

          qtmedia Enable playback via Qt5Multimedia

          kwrite

          activities Enable Plasma Activities support via kde-frameworks/kactivities

          libkdepim

          designer Build plugins for dev-qt/designer

          libkleo

          fancyviewer Use kde-apps/kpimtextedit for an improved audit log viewer

          libksane

          kwallet Enable encrypted storage of passwords with kde-frameworks/kwallet

          mailcommon

          designer Build plugins for dev-qt/designer

          marble

          aprs Enable support for APRS data sources
          designer Install plugin for dev-qt/designer
          geolocation Enable position information via dev-qt/qtpositioning
          phonon Enable sound support via media-libs/phonon
          shapefile Enable support for ESRI shapefiles
          webengine Use dev-qt/qtwebengine for embedded web browser

          okular

          chm Enable support for Microsoft Compiled HTML Help files
          epub Enable E-Book support via app-text/ebook-tools
          image-backend Enable image viewing support
          markdown Enable Markdown support via app-text/discount
          mobi Enable mobipocket support
          mobile Enable Plasma mobile support
          plucker Enable Plucker E-Book for Palm OS devices support
          share Enable support for a share menu using kde-frameworks/purpose
          speech Enable text-to-speech support

          pimcommon

          designer Build plugins for dev-qt/designer

          spectacle

          kipi Enable support for the KDE Image Plugin Interface
          share Enable support for a share menu using kde-frameworks/purpose

          step

          qalculate Enable the libqalculate library for unit conversion

          yakuake

          absolute-position Use kde-frameworks/kwayland for absolute window positioning in KWin

          kde-frameworks

          frameworkintegration

          appstream Enable AppStream software metadata support

          kcompletion

          designer Build plugins for dev-qt/designer

          kconfigwidgets

          designer Build plugins for dev-qt/designer
          man Build and install man pages

          kded

          man Build and install man pages

          kdewebkit

          designer Build plugins for dev-qt/designer

          kfilemetadata

          epub Enable support for reading EPUB ebook metadata
          office Enable support for reading ODF and OOXML metadata

          kiconthemes

          designer Build plugins for dev-qt/designer

          kimageformats

          eps Support the EPS graphics file format

          kinit

          caps Capabilities support for improved security and better OOM handling
          man Build and install man pages

          kio

          designer Build plugins for dev-qt/designer
          kwallet Enable permanent storage of passwords for kpasswdserver with kde-frameworks/kwallet

          kitemviews

          designer Build plugins for dev-qt/designer

          knotifications

          phonon Play notification sounds via media-libs/phonon instead of media-libs/libcanberra
          speech Enable text-to-speech notification support

          knotifyconfig

          phonon Add sound support via media-libs/phonon

          kpackage

          man Build and install man pages

          kplotting

          designer Build plugins for dev-qt/designer

          kservice

          man Build and install man pages

          ktexteditor

          editorconfig 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          ktextwidgets

          designer Build plugins for dev-qt/designer
          speech Enable text-to-speech support

          kwallet

          gpg Support wallets with GnuPG encryption in addition to the default blowfish-encrypted file
          man Build and install man pages

          kwidgetsaddons

          designer Build plugins for dev-qt/designer

          kxmlgui

          attica Enable support for kde-frameworks/attica
          designer Build plugins for dev-qt/designer

          networkmanager-qt

          teamd Enable Teamd control support

          plasma

          gles2 Use GLES 2.0 or later instead of full OpenGL

          prison

          qml Enable QML/QtQuick support via dev-qt/qtdeclarative

          purpose

          dolphin Enable support for sharing files from kde-apps/dolphin
          kaccounts Enable support for system-wide defined KAccounts

          sonnet

          aspell Enable the app-text/aspell spell-checking backend
          designer Build plugins for dev-qt/designer
          hunspell Enable the app-text/hunspell spell-checking backend

          kde-misc

          kdeconnect

          app Enable experimental kcapp frontend
          mousepad Enable remote mousepad plugin using x11-libs/libfakekey
          wayland Enable kwin_wayland support for mousepad plugin using kde-frameworks/kwayland

          kimtoy

          scim Enable Smart Common Input Method support

          kio-gdrive

          kaccounts Use kde-apps/kaccounts-integration backend (default) instead of dev-libs/qtkeychain

          kmarkdownwebview

          webkit Use dev-qt/qtwebkit instead of dev-qt/qtwebengine

          tellico

          discid Add support for reading disc IDs from audio CDs
          yaz Add support for searching Z39.50 databases

          kde-plasma

          discover

          firmware Enable support for firmware upgrades using sys-apps/fwupd

          kde-cli-tools

          kdesu Build graphical frontend for kde-frameworks/kdesu

          kdeplasma-addons

          share Enable applet for quickly sharing data to a variety of sources
          webengine Enable dictionary and web browser applets using dev-qt/qtwebengine

          kinfocenter

          gles2 Show OpenGL ES information in kinfocenter
          pci Show advanced PCI information

          kmenuedit

          hotkeys Enable support for hotkey editing

          kscreenlocker

          consolekit Support for killing the screenlocker when sys-auth/consolekit is the session tracker

          kwin

          gles2 Use OpenGL ES 2 instead of full GL
          multimedia Enable effect video button in desktop effects KCM

          libksysguard

          webengine Enable display of detailed memory information using dev-qt/qtwebengine.

          plasma-desktop

          appstream Enable AppStream software metadata support
          ibus Use ibus input method via app-i18n/ibus
          mouse Enable mouse KCM
          scim Enable applets that use app-i18n/scim
          touchpad Enable touchpad KCM

          plasma-meta

          browser-integration Enable integration with Chrome/Firefox with browser extensions
          consolekit Enable sys-auth/consolekit support instead of logind session tracking
          crypt Pull in kde-plasma/plasma-vault for encrypted vaults integration
          desktop-portal Enable sys-apps/xdg-desktop-portal backend implementation for Plasma
          discover Pull in resources management GUI; a centralised GHNS alternative and optional sys-apps/fwupd frontend
          display-manager Pull in a graphical display manager
          elogind Use sys-auth/elogind for session tracking
          grub Pull in Breeze theme for sys-boot/grub
          gtk Enable Breeze widget style and system settings module for GTK+
          legacy-systray Add support for legacy applications using kde-plasma/xembed-sni-proxy
          pam Enable support for kwallet auto-unlocking
          plymouth Pull in Breeze theme for sys-boot/plymouth
          pm-utils Enable support for suspend/resume with sys-power/pm-utils when using sys-auth/consolekit
          pulseaudio Install Plasma applet for PulseAudio volume management
          qrcode Enable support for easy WiFi network sharing using QR codes with kde-plasma/plasma-nm
          sddm Pull in the x11-misc/sddm display manager and system settings module
          sdk Pull in kde-plasma/plasma-sdk for Plasma development
          thunderbolt Pull in kde-plasma/plasma-thunderbolt control center module
          wallpapers Install wallpapers for the Plasma Workspace

          plasma-nm

          modemmanager Enable support for mobile broadband devices
          openconnect Build support for the OpenConnect VPN client
          teamd Enable Teamd control support

          plasma-workspace

          appstream Enable AppStream software metadata support
          geolocation Enables dataengine providing location information
          qalculate Enable Qalculate runner using sci-libs/libqalculate
          qrcode Enable support for creating QR codes from clipboard data using kde-frameworks/prison

          powerdevil

          brightness-control Enable screen brightness control using app-misc/ddcutil
          wireless Enable wireless energy saving actions via kde-frameworks/bluez-qt and kde-frameworks/networkmanager-qt

          xdg-desktop-portal-kde

          screencast Enable screencast portal using media-video/ 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          lxde-base

          lxdm

          consolekit Enables support for authorization using consolekit
          gtk3 Use GTK+3 instead of 2

          lxterminal

          gtk3 Use GTK+3 instead of GTK+2

          lxqt-base

          lxqt-config

          monitor Build monitor settings tool
          touchpad Build touchpad settings tool

          lxqt-meta

          about Install lxqt-base/lxqt-about
          admin Install lxqt-base/lxqt-admin
          filemanager Install x11-misc/pcmanfm-qtfile manager
          lightdm Install x11-misc/lightdmdisplay manager
          lximage Install media-gfx/lximage-qtimage viewer
          minimal Do not install x11-wm/openboxwindow manager
          nls Install dev-qt/qttranslations to better support different locales
          powermanagement Install lxqt-base/lxqt-powermanagement package
          processviewer Install x11-misc/qps package
          screenshot Install x11-misc/screengrab package
          sddm Install x11-misc/sddm display manager
          ssh-askpass Install lxqt-base/lxqt-openssh-askpass user password prompt tool
          sudo Install lxqt-base/lxqt-sudo
          terminal Install x11-terms/qterminal package
          trash Install gnome-base/gvfs to enable 'trash' functionality in x11-misc/pcmanfm-qt

          lxqt-panel

          colorpicker Build colorpicker plugin
          cpuload Build cpuload plugin
          desktopswitch Build desktopswitch plugin
          directorymenu Build directorymenu plugin
          dom Build dom plugin
          kbindicator Build kbindicator plugin
          mainmenu Build mainmenu plugin
          mount Build mount plugin
          networkmonitor Build networkmonitor plugin
          quicklaunch Build quicklaunch plugin
          sensors Build sensors plugin
          showdesktop Build showdesktop plugin
          spacer Build spacer plugin
          statusnotifier Build statusnotifier plugin
          sysstat Build sysstat plugin
          taskbar Build taskbar plugin
          tray Build tray plugin
          volume Build volume plugin
          worldclock Build worldclock plugin

          lxqt-session

          themes Install LXQt themes and graphics

          mail-client

          alot

          doc Install user manual and API documentation

          alpine

          chappa enhance alpine by applying Eduardo Chappa's patches
          onlyalpine installs only the alpine binary, so it does not collied with pico and/or pine
          passfile Adds support for caching passwords into a file between sessions
          smime Enable support for S/MIME

          balsa

          crypt Adds support for GnuPG encryption
          rubrica Adds support for rubrica addressbook

          claws-mail

          archive Enable archiving plugin
          bogofilter Build mail-filter/bogofilter plugin
          dillo Enable dillo html viewer plugin
          gdata Enable plugin for access to Google data providers
          gtk3 Build support for GTK+3
          libcanberra Enable sound notification in connection with USE=notification
          libindicate Enable notification through DBUS in connection with USE=notification
          libnotify Enable notification on the desktop in connection with USE=notification
          litehtml Enable dev-libs/gumbo html viewer plugin
          notification Notification for new mail in different way, see also USE flags libcanberra, libindicate and libnotify
          pgp Enable PGP support
          sieve Build plugin for sieve filter support
          smime Build plugin for S/MIME support
          spam-report Enable plugin for spam reporting to various services
          spamassassin Build mail-filter/spamassassin plugin
          valgrind Add support for memory debugging using valgrind

          evolution

          archive Enable archives support in attachments via app-arch/gnome-autoar
          bogofilter Build mail-filter/bogofilter plugin
          geolocation Enable support for displaying contacts on a map inside evolution using media-libs/libchamplain
          highlight Enable text highlighting plugin
          ldap Enable support for fetching contacts from an LDAP or Active Directory server using net-nds/openldap
          spamassassin Build mail-filter/spamassassin plugin
          weather Enable optional weather calendar support
          ytnef Enable optional TNEF attachments parser support using net-mail/ytnef

          geary

          ytnef Enable optional TNEF attachments parser support using net-mail/ytnef

          mail-notification

          sylpheed Enable support for MH mailboxes used by mail-client/sylpheed

          mutt

          berkdb Enable sys-libs/db database backend for header caching
          gdbm Enable sys-libs/gdbm database backend for header caching
          gpg Enable support for app-crypt/gpgme
          gpgme Build gpgme backend to support S/MIME, PGP/MIME and traditional/inline PGP
          hcache Enable header cache, one database backend needs to be enabled
          lmdb Enable dev-db/lmdb database backend for header caching
          notmuch Enable support for net-mail/notmuch
          pgp-classic Build classic_pgp backend to support PGP/MIME and traditional/inline PGP
          pgp_classic Build classic_pgp backend to support PGP/MIME and traditional/inline PGP
          pop Enable support for POP3 mailboxes
          smime Enable support for smime
          smime-classic Build classic_smime backend to support S/MIME
          smime_classic Build classic_smime backend to support S/MIME
          smtp Enable support for direct SMTP delivery
          tokyocabinet Enable dev-db/tokyocabinet database backend for header caching

          neomutt

          berkdb Enable BDB (Berkley DB) backend for header caching
          gdbm Enable GDBM (GNU dbm) backend for header caching
          gpg Enable support for app-crypt/gpgme
          gpgme Build gpgme backend to support S/MIME, PGP/MIME and traditional/inline PGP
          kyotocabinet Enable Kyoto Cabinet database backend for header caching
          lmdb Enable LMDB (Lightning Memory-Mapped Database) backend for header caching
          notmuch Enable support for net-mail/notmuch
          pgp-classic Build classic_pgp backend to support PGP/MIME and traditional/inline PGP
          pgp_classic Build classic_pgp backend to support PGP/MIME and traditional/inline PGP
          qdbm Enable QDBM (Quicker Database Manager) database backend for header caching
          smime Enable support for smime
          smime-classic Build classic_smime backend to support S/MIME
          smime_classic Build classic_smime backend to support S/MIME
          tokyocabinet Enable Tokyo Cabinet database backend for header caching

          roundcube

          change-password Allow users to change passwords through Roundcube
          enigma Add dependencies to support server-side GnuPG signing and/or encryption through the enigma plugin
          ldap Add dependencies to support connecting to an LDAP address book server
          managesieve Add dependencies to support the sieverules plugin

          s-nail

          kerberos If network is enabled, this adds support for GSSAPI login on IMAP through virtual/krb5.
          net Enable support for network protocols (POP, IMAP and SMTP). If you only need to send mail with the local Transport Agent, disabling this will get you support for only /usr/sbin/sendmail call.
          ssl If network is enabled, this adds support for S/MIME and SSL/TLS-powered protocols through dev-libs/openssl.

          sylpheed

          oniguruma Use dev-libs/oniguruma for regular expression

          thunderbird

          bindist 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          clang Use Clang compiler instead of GCC
          custom-optimization Build with user-specified compiler optimizations (-Os, -O0, -O1, -O2, -O3) from CFLAGS (unsupported)
          eme-free Disable EME (DRM plugin) cabability at build time
          gmp-autoupdate Allow Gecko Media Plugins (binary blobs) to be automatically downloaded and kept up-to-date in user profiles
          gtk2 Use the cairo-gtk2 rendering engine instead of the default cairo-gtk3
          lightning Enable app-global calendar support (note 38.0 and above bundles calendar support when this flag is off)
          lto Enable Link Time Optimization (LTO). Requires Gold linker when using GCC or LDD linker when using Clang
          mozdom Enable Mozilla's DOM inspector
          pgo Add support for profile-guided optimization using gcc-4.5, for faster binaries. This option will double the compile time.
          rust Enable support for using rust compiler (experimental)
          system-av1 Use the system-wide media-libs/dav1d and media-libs/libaom library instead of bundled.
          system-cairo Use the system-wide x11-libs/cairo instead of bundled.
          system-harfbuzz Use the system-wide media-libs/harfbuzz and media-gfx/graphite2 instead of bundled.
          system-icu Use the system-wide dev-libs/icu instead of bundled.
          system-jpeg Use the system-wide media-libs/libjpeg-turbo instead of bundled.
          system-libevent Use the system-wide dev-libs/libevent instead of bundled.
          system-libvpx Use the system-wide media-libs/libvpx instead of bundled.
          system-sqlite Use the system-wide dev-db/sqlite installation with secure-delete enabled
          system-webp Use the system-wide media-libs/libwebp instead of bundled.

          thunderbird-bin

          crashreporter Enable crash reporter for bugs

          trojita

          password Store passwords securely via dev-libs/qtkeychain
          pim Enable support for KDE PIM resources integration via kde-apps/akonadi addressbook plugin

          mail-filter

          MailScanner

          exim Set mail-mta/exim to used MTA
          postfix Set mail-mta/postfix to used MTA
          spamassassin Enable usage of mail-filter/spamassassin for spam protection

          amavisd-new

          courier Add courier support
          dkim Add DomainKeys Identified Mail support
          qmail Add qmail support
          razor Add support for mail-filter/razor
          rspamd Add support for mail-filter/rspamd extension (HTTP only)
          rspamd-https Add support for mail-filter/rspamd extension (both HTTP and HTTPS)
          spamassassin Add support for mail-filter/spamassassin
          zmq Add support for zeromq sockets

          bogofilter

          tokyocabinet Enable Tokyo Cabinet database support

          dcc

          rrdtool Enable net-analyzer/rrdtool interface scripts

          dspam

          daemon Enable support for DSPAM to run in --daemon mode
          debug Enable debugging support (don't enable this unless something needs testing!)
          domain-scale Build for domain scale setups - puts data to $HOME/data/domain.com/user
          hash Enable support for the file-orientated hash driver
          large-scale Build for large scale setups - puts data to $HOME/data/u/s/user
          small-scale Build for small scale setups - puts data to $HOME/data/user
          user-homedirs Build with user homedir support
          virtual-users Build with virtual-users support

          libmilter

          poll Use poll instead of select

          maildrop

          authlib Add courier-authlib support
          dovecot Add dovecot authentication support
          tools Install maildirmake and deliverquota tools
          trashquota Count deleted messages as part of the maildir quota

          mimedefang

          poll Use poll instead of select

          opendkim

          ldap Enable openldap as a dataset facilitator or keys, determining domains to sign for, and any other dataset that opendkim supports.
          lmdb Add support for using dev-db/lmdb
          lua Enables control over signature verification, filtering and policy to be controlled by user defined lua scripts.
          memcached Add support for using dev-libs/libmemcached
          opendbx Use opendbx backend to facilitate dataset driven OpenDKIM configuration options like stats, bodylengthdb, etc. against a wide variety of database types
          poll Use poll() instead of select() for the provided asynchronous resolver library.
          query_cache Obsolete, use "querycache" instead. Flag will be removed after next stabilization.
          querycache Add support for query caching (requires 'berkdb' flag)
          sasl Used to authenticate to a LDAP server in various ways if required.
          stats Add support for statistics (requires 'opendbx' flag)
          unbound Use the unbound dnssec library to perform DKIM DNS queries.

          opendmarc

          reports Install the reports binaries: expire, import, reports, params
          spf Use the mail-filter/libspf2 for Sender Policy Framework checking

          postfwd

          tools Install additional tools for testing postfwd

          postgrey

          targrey Enables the targrey patch

          rmilter

          dkim Enable support for DomainKeys Identified Mail
          memcached Enable support for memcached

          rspamd

          fann Enable neural network plugin (requires sci-mathematics/fann).
          pcre2 Use dev-libs/libpcre2
          torch Enable torch support. This is required for the neural module

          spamassassin

          cron Install a cron job to update SpamAssassin's rules daily.
          qmail Build qmail functionality and docs

          spamdyke

          ssl Enables TLS protocol for spamdyke

          mail-mta

          courier

          fax Enables fax support in the courier mail server
          norewrite 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          web Enable the web interface
          webmail Enable the webmail interface

          exim

          arc Adds support for Authenticated Receive Chain (ARC)
          dane Adds support for DNS-based Authentication of Named Entities
          dcc Adds support for Distributed Checksum Clearinghouse (DCC)
          dkim Adds support for DomainKeys Identified Mail (DKIM)
          dlfunc Install local_scan.h header to compile separate dlfunc libraries
          dmarc Adds support for DMARC
          dnsdb Adds support for a DNS search for a record whose domain name is the supplied query
          dovecot-sasl Adds support for Dovecot's authentication
          dsn Adds support for Delivery Status Notifications (DSN)
          exiscan-acl Patch providing support for content scanning
          lmtp Adds support for lmtp
          mbx Adds support for UW's mbx format
          pkcs11 Require pkcs11 support in net-libs/gnutls with USE=gnutls
          prdr Adds support for Per-Recipient Data Response
          proxy Add support for being behind a proxy, such as HAProxy
          redis Adds support for querying dev-db/redis
          spf Adds support for Sender Policy Framework
          srs Adds support for Sender Rewriting Scheme
          tpda Adds support for Transport Post-Delivery Actions

          msmtp

          daemon Build/install msmtpd MTA daemon
          mta Enable this to install as system-wide MTA

          netqmail

          authcram Enable AUTHCRAM support
          gencertdaily Generate SSL certificates daily instead of hourly
          highvolume Prepare netqmail for high volume servers
          pop3 Include POP3 server

          opensmtpd

          mta Enable this to install as system-wide MTA

          postfix

          dovecot-sasl Enable net-mail/dovecot protocol version 1 (server only) SASL implementation
          eai Add support for SMTPUTF8
          ldap-bind Add support for binding to LDAP backend using dev-libs/cyrus-sasl
          lmdb Add support for using dev-db/lmdb for lookup tables
          memcached Add support for using net-misc/memcached for lookup tables

          qpsmtpd

          postfix 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          ssmtp

          mta Install symlinks for sendmail-compatible MTA.

          mate-base

          caja

          mate Install x11-themes/mate-icon-theme which is needed when this package is used in the MATE desktop environment.
          packagekit Enable support for installing via app-admin/packagekit based on mimetype

          mate

          base Install base MATE Desktop applications that are recommended for the most common usage; for example, this installs the file manager. Disable this and other USE flags if you want a more minimal MATE Desktop.
          extras Install additional MATE Desktop applications that are recommended for extended usage of the MATE Desktop as upstream sees it; for example, this installs MATE Desktop's office related applications. Disable this if you plan to use your own non-MATE Desktop alternatives or a custom mixture of MATE and non-MATE packages.
          help Install gnome-extra/yelp to handle in application help menus and documentation browsing
          notification Force notification daemon to default to MATE's notification daemon. Enabled by default. Disable if it causes conflicts with other installed desktop environments.
          themes Install MATE Desktop's themes; if you use other themes, you can disable this to spare some space and time.

          mate-applets-meta

          appindicator Pull in mate-extra/mate-indicator-applet for AppIndicator applet
          sensors Pull in mate-extra/mate-sensors-applet for hw sensors applet

          mate-control-center

          accountsservice Add support for AccountsService
          appindicator Add support for AppIndicator

          mate-session-manager

          xtrans Build with Xtrans support; WARNING: Disabling this flag will result in ICE binding on all interfaces

          mate-settings-daemon

          rfkill build support for rfkill

          mate-extra

          caja-extensions

          cdr Add an extension to burn files to cds using app-cdr/brasero.
          gajim Add an extension to support net-im/gajim.
          image-converter Add image conversion support.
          mail Add an extension to support e-mail functionality.
          open-terminal Add an extension to support an open terminal.
          pidgin Add an extension to support net-im/pidgin
          share Add an extension to support sharing files.
          wallpaper Add an extension to support setting an image as the current wallpaper

          mate-polkit

          accountsservice Support extraction of data from AccountsService
          appindicator Add support for AppIndicator

          mate-power-manager

          applet Enable building of the MATE applet.

          mate-screensaver

          consolekit Enable support for sys-auth/consolekit

          mate-utils

          applet Enable the mate dictionary applet

          media-fonts

          corefonts

          tahoma Also install the Tahoma font. Due to the lack of a free bold variant, this may render badly. See bug 184790.

          culmus

          ancient Install ancient semitic scripts
          fancy Install fancy fonts
          fontforge Use media-gfx/fontforge to build fonts from source
          taamey Install taamey fonts

          dejavu

          fontforge Use media-gfx/fontforge to build fonts from source

          fontawesome

          otf Install the OpenType version of the font
          ttf Install the TrueType version of the font

          ibm-plex

          otf Install OTF fonts
          ttf Install TTF fonts

          infinality-ultimate-meta

          free Install fonts for the "free" preset
          latin Install additional latin fonts
          minimal Install a minimal set of fonts
          ms Install (free) fonts for the "ms" preset

          intlfonts

          bdf Installs BDF fonts in addition to PCF

          liberation-fonts

          fontforge Use media-gfx/fontforge to build fonts from source

          montecarlo

          bdf Install BDF fonts in addition to PCF

          mplus-outline-fonts

          ipafont Generates new fonts merged with media-fonts/ja-ipafonts

          noto

          extra Install full upstream font set

          sil-charis

          compact Use more compactly spaced font

          sil-gentium

          compact Also install more compact version of the font.

          terminus-font

          a-like-o Changes view of letter 'a' - a looks like o (see homepage)
          center-tilde Place the '~' character vertically centered on the line instead of to the top.
          distinct-l ll2 variant with more distinctive l (lowercase L)
          pcf Install Portable Compiled Font (PCF) (required for X11)
          pcf-unicode-only Remove non-unicode PCF fonts that could be problematic. See bug #520222.
          psf Install PC Screen Font (PSF) with unicode data (for linux console)
          quote Changes view of quotes: symmetric ` and ' instead of asymmetric one (see homepage)
          ru-dv Changes view of Russian letters 'de' and 've' (see homepage)
          ru-g Changes view of Russian letter 'ge' (see homepage)
          ru-i Changes view of Russian letter 'i' - not like Latin u, but like "mirrored" N (see homepage)
          ru-k Changes view of Russian letter 'k' (see homepage)

          unifont

          fontforge Use media-gfx/fontforge to build fonts from source
          utils Install unifont utilities

          media-gfx

          ahoviewer

          libsecret Support password storing using libsecret
          rar Rar archive support
          zip Zip archive support

          album

          plugins Install optional plugins
          themes Install optional themes

          alembic

          arnold Add support for arnold renderer (experimental)
          boost Use dev-libs/boost library
          examples Install alembic examples
          hdf5 Add support sci-libs/hdf5
          maya Compile Alembic plugin for Maya (experimental)
          prman Compile Alembic plugin for Renderman (experimental)
          python Build pyalembic python bindings (needs dev-python/pyilmbase)
          test Build and run the test-suite
          zlib Use sys-libs/zlib for compressions

          apngasm

          7z Enable support for 7zip compression
          zopfli Enable support for Zopfli compression

          asymptote

          boehm-gc Enables using the Boehm-Demers-Weiser conservative garbage collector
          offscreen Enables off-screen rendering
          sigsegv Enables using dev-libs/libsigsegv

          blender

          bullet Enable Bullet (Physics Engine).
          collada Add support for Collada interchange format through media-libs/opencollada.
          color-management Enable color management via media-libs/opencolorio.
          cuda Build cycles renderer with nVidia CUDA support.
          cycles Build cycles renderer (requires media-libs/openimageio and dev-libs/boost).
          dds Adds DDS textures support to Blender.
          doc Build C and Python API documentation directly from the source code.
          elbeem Adds surface fluid simulation to Blender using El'Beem library.
          game-engine Adds Game Engine support to Blender.
          headless Build without graphical support (renderfarm, server mode only).
          llvm Enable features depending on llvm.
          man Build and install man pages.
          ndof Enable NDOF input devices (SpaceNavigator and friends).
          opencl Allow OpenCL Graphics Acceleration. This may require extra graphics card drivers.
          openimageio Enable OpenImageIO Support
          opensubdiv Add rendering support form OpenSubdiv from Dreamworks Animation through media-libs/opensubdiv.
          openvdb Add GPU preview rendering. Only works with nVidia cards.
          osl Add support for OpenShadingLanguage scripting.
          player Build the Blender Player. THis requires the Game engine.
          test Build the provided unit tests.
          valgrind Add support for memory debugging using dev-util/valgrind

          chafa

          tools Build command-line tools

          comix

          rar Pulls app-arch/unrar for rar file support

          cura

          usb Access 3D printers via USB

          darktable

          flickr Add support for uploading photos to flickr
          geolocation Enable geotagging support
          kwallet Enable encrypted storage of passwords with kde-frameworks/kwallet
          opencl Enable opencl support
          pax_kernel Triggers paxmarking of main darktable binary

          digikam

          addressbook Enable akonadi contact integration
          dnn Build neural network faces engine module
          imagemagick Enable support for additional image formats such as XCF, FITS, HEIC etc.
          lensfun Enable support for media-libs/lensfun
          marble Enable support for geolocation using kde-apps/marble
          mediaplayer Enable support for media player using media-libs/qtav
          panorama Build the panorama plugin which requires media-gfx/hugin
          semantic-desktop Enable kde-frameworks/kfilemetadata support
          vkontakte Build net-libs/libkvkontakte plugin for vkontakte.ru
          webkit Build with dev-qt/qtwebkit instead of dev-qt/qtwebengine

          eog-plugins

          map Enable world map display using media-libs/libchamplain
          picasa Enable uploading to Google's Picasa Web Albums

          exact-image

          swig Adds Swig support dev-lang/swig

          exiv2

          webready Support reading metadata over the internet

          fbida

          X Install the Motif based image viewer "ida"
          fbcon Install the framebuffer image viewer "fbi"
          ghostscript 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          fim

          bmp Enable BMP file support
          dia Enable DIA file support via app-office/dia
          imagemagick Use convert from media-gfx/imagemagick as fallback file opener
          pcx Enable PCX file support
          xfig Enable FIG file support via media-gfx/xfig

          fontforge

          truetype-debugger Enable truetype debugger in fontforge

          fotowall

          webcam Enable webcam support

          freewrl

          glew Enable glew extensions
          java Build and install java EAI/SAI support library
          libeai Build EAI C library
          opencl Enable OpenCL support
          osc Allows for OSC-based control and communication between multiple freewrl instances
          rbp Enable support for Rigid Body Physics

          geeqie

          ffmpegthumbnailer Enable video thumbnail support with media-video/ffmpegthumbnailer
          gpu-accel Enable GPU acceleration support - experimental
          gtk3 Link against x11-libs/gtk+:3 instead of x11-libs/gtk+:2
          map Enable items map display - experimental

          gimp

          heif Enable support for ISO/IEC 23008-12:2017 HEIF files
          smp Enable support for multiprocessors
          vector-icons Enable support for vector icons (experimental)

          gmic

          cli Build CLI interface
          krita Build media-gfx/krita plugin
          opencv Enable support for webcams using the OpenCV library

          gnome-photos

          flickr Ensure runtime Flickr support

          graphicsmagick

          fpx Enable FlashPix support with media-libs/libfpx
          modules Compile graphicsmagick with dynamically loadable modules
          q16 Set storage quantum size to 16 (~2*memory)
          q32 Set storage quantum size to 32 (~5*memory)

          graphviz

          X Builds lefty front-end, builds plugin -Txlib, and enables support for x11 in various other modules (needs cairo)
          devil Enables DevIL output plugin -Tdevil
          gdk-pixbuf Enables gdk-pixbuf2 plugin
          gtk Enables gtk+ output plugin -Tgtk (needs cairo)
          gts Enables support for GNU Triangulated Surface Library (required for sfdp to work)
          lasi Enables PostScript output via media-libs/lasi, for plugin -Tlasi (needs cairo)

          gthumb

          http Enable webservice integration through net-libs/libsoup
          json Compile code that uses the libjson-glib library
          slideshow Enable slideshow plugin

          hugin

          sift automatically align images with media-gfx/autopano-sift-C

          imagemagick

          corefonts Use media-fonts/corefonts which is required by some commands
          fpx Enable media-libs/libfpx support
          hdri Enable High Dynamic Range Images formats
          heif Enable support for ISO/IEC 23008-12:2017 HEIF/HEIC image format using media-libs/libheif
          lqr Enable experimental liquid rescale support using media-libs/liblqr
          opencl Enable OpenCL support
          pango Enable Pango support using x11-libs/pango
          q32 Set quantum depth value to 32
          q8 Set quantum depth value to 8

          inkscape

          cdr Enable support for CorelDRAW Diagrams via media-libs/libcdr
          dia pull in app-office/dia for dia import extension
          inkjar Enable support for OpenOffice.org SVG jar files
          latex pull in dependencies for LaTeX formulas
          svg2 Enable support for new SVG2 features
          visio Enable support for Microsoft Visio Diagrams via media-libs/libvisio
          wpg Enable support for WordPerfect Graphics via app-text/libwpg

          iscan-plugin-gt-f500

          minimal Install the firmware only, and not the plugin.

          jpeg2ps

          metric Default to A4 paper size

          kphotoalbum

          kipi Support for the KDE Image Plugin Interface
          map Enable map display support using kde-apps/libkgeomap

          krita

          color-management Enable color management via media-libs/opencolorio
          heif Enable support for ISO/IEC 23008-12:2017 HEIF/HEIC image format using media-libs/libheif
          qtmedia Enable sound support for animations via dev-qt/qtmultimedia
          vc Enable support for dev-libs/vc, could be a significant speed boost

          librecad

          3d Require all 2D coordinates stored as 3D
          tools Build additional tool programs: tff2lff

          luminance-hdr

          fits 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          mandelbulber

          opencl Enable GPU rendering support using OpenCL

          nomacs

          opencv Build support for media-libs/opencv

          nvidia-texture-tools

          cg Enable NVIDIA C graphics compiler toolkit plug-in
          glew Enable support for The OpenGL Extension Wrangler Library (media-libs/glew)

          openclipart

          gzip Compresses clip art using gzip

          openexr_viewers

          cg Add support for nvidia's cg shaders

          openvdb

          abi3-compat Disables newer features to maintain compatibility with ABI3. Enabled by default.
          abi4-compat Disables newer features to maintain compatibility with ABI4. Enabled by default.

          photoqt

          devil Support additional image formats using media-libs/devil
          freeimage Support additional image formats using media-libs/freeimage

          pngcrush

          system-libs Use libpng and libz provided by system

          potrace

          metric default to a4 paper size and metric measurement

          povray

          io-restrictions POV-Ray's mechanism for control of I/O operations
          mkl Enable support for Intel Vector Math Library, part of sci-libs/mkl

          pqiv

          archive Enable support for images in archives and cbX comic book files

          pstoedit

          emf Enable media-libs/libemf support
          pptx Enable support for generating PowerPoint pptx files

          qimgv

          video Add support for gif/webm playback via libmpv

          shotwell

          opencv Enable face detection via media-libs/opencv

          sigal

          s3 Enables support for the Amazon S3 service.

          slic3r

          gui Enable GUI

          ufraw

          contrast enable contrast setting option
          fits Enable support for the FITS image format through sci-libs/cfitsio
          timezone enable DST correction for file timestamps

          xpaint

          pgf Support for loading PGF images

          xsane

          ocr Enable support for Optical Character Recognition reader

          yafaray

          blender Install addon for media-gfx/blender
          fastmath Enable mathematic approximations to make code faster
          fasttrig Enable trigonometric approximations to make code faster
          opencv Use media-libs/opencv

          media-libs

          a52dec

          djbfft Prefer D.J. Bernstein's library for fourier transforms

          allegro

          dumb Enable media-libs/dumb module library support
          physfs Enable physfs support
          vga Enables the VGA graphics driver

          alsa-lib

          alisp Enable support for ALISP (ALSA LISP) interpreter for advanced features.
          thread-safety thread-safe API functions

          alure

          dumb Enable media-libs/dumb module library support
          fluidsynth Enables Fluidsynth MIDI software synthesis

          assimp

          samples Build viewer library
          tools Build assimp tool binary

          aubio

          double-precision Compile in double precision mode.

          avidemux-core

          nvenc Adds support for NVIDIA Encoder (NVENC) API for hardware accelerated encoding on NVIDIA cards.
          system-ffmpeg Use the ffmpeg provided by the system.

          avidemux-plugins

          aften Enable A/52 (AC-3) audio encoder support.
          amr Enable Adaptive Multi-Rate format support via media-libs/opencore-amr.
          dcaenc Enable DTS Coherent Acoustics audio encoder support via media-sound/dcaenc.
          fdk Adds support for encoding AAC using media-libs/fdk-aac.
          fribidi Enable unicode bidirectional algorithm support via dev-libs/fribidi.
          nvenc Adds support for NVIDIA Encoder (NVENC) API for hardware accelerated encoding on NVIDIA cards.
          twolame Enable TwoLAME support via media-sound/twolame, an optimised MPEG Audio Layer 2 (MP2) encoder.
          vpx Enable WebM VP8 Codec SDK support via media-libs/libvpx.
          x265 Enables HEVC support with media-libs/x265.

          cal3d

          16bit-indices Enables use of 16bit indices

          chromaprint

          tools Build and install fpcalc and fpcollect tools

          clutter

          egl Enable EGL backend.
          gtk Use gdk-pixbuf from x11-libs/gtk+ as image rendering backend

          cogl

          gles2 Enable OpenGL ES 2.0 support
          kms Enable KMS support.
          pango Build cogl-pango library for x11-libs/pango integration

          coin

          exceptions Compile with C++ exceptions
          man Build and install man pages
          qthelp Build API documentation in QtHelp format
          simage Texture loading via media-libs/simage library

          dav1d

          10bit Add support for building 10-bit and 12-bit AV1.
          8bit Add support for decoding 8-bit AV1.
          asm Enable custom assembly for faster decoding.

          devil

          allegro Add support for Allegro
          nvtt Add support for media-gfx/nvidia-texture-tools

          esdl

          image Enable image support

          faad2

          digitalradio Digital Radio Mondiale (warning: disables other decoders)

          flickcurl

          raptor Use media-libs/raptor for proper RDF serializing

          fontconfig-infinality

          nyx Additional style using croscorefonts

          freetype

          adobe-cff Use Adobe CFF as default font-renderer
          bindist Disable ClearType support (see //freetype.org/patents.html)
          bzip2 Support bzip2 compressed PCF fonts.
          cleartype_hinting New bytecode hinting mode for TrueType fonts that activates subpixel hinting (a.k.a. ClearType hinting) by default
          fontforge Install internal headers required for TrueType debugger in media-gfx/fontforge (built with USE=truetype-debugger)
          harfbuzz Use media-libs/harfbuzz for auto-hinting OpenType fonts. WARNING: may trigger circular dependencies!
          infinality Enable infinality options for improved LCD filtering
          utils Install utilities and examples from ft2demos

          freeverb3

          audacious Build Audacious plugin
          forcefpu Disable assembly code
          plugdouble Build plugins in double precision mode (default is float)

          ganv

          fdgl Use experimental force-directed graph layout

          gd

          webp Enable support for the webp format

          gegl

          lensfun Enable support for media-libs/lensfun.
          umfpack Enable sparse solving via sci-libs/umfpack.

          giflib

          rle Build converters for RLE format (utah raster toolkit)

          gmtk

          dconf Enable support for gnome-base/dconf

          grilo

          network Enable network access for media discovery using net-libs/libsoup
          playlist Enable support for playlists through dev-libs/totem-pl-parser

          gst-plugins-bad

          bzip2 Enable bzip2 encoder/decoder plugin
          egl Enable EGL support
          gles2 Enable GLES2 support

          gst-plugins-base

          X 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          egl Enable EGL platform support
          gbm Enable Graphics Buffer Manager based EGL windowing system support (requires egl and at least one of gles or opengl)
          gles2 Enable OpenGL library and plugin via GLESv2 API (requires egl)
          ivorbis Enable integer based vorbis decoder
          opengl Enable OpenGL library and plugin via desktop OpenGL API
          pango Enable pango GStreamer plugin
          wayland Enable Wayland EGL windowing system support (requires egl and at least one of gles2 or opengl)

          gstreamer

          orc Disable some PaX memory protections to allow plugins that use dev-lang/orc for runtime optimization to be used on hardened PaX systems
          unwind Enable sys-libs/libunwind usage for better backtrace support in leaks tracer module

          harfbuzz

          glib Compile with GLib Unicode support
          graphite Use graphite to render complex non-Roman writing systems

          imlib2

          X Use the X window system
          bzip2 Bzip2 loader support
          gif Gif image loader support
          jpeg Jpeg image loader support
          mp3 ID3 loader support
          png PNG image loader support
          shm Use MIT shared memory support for X image transfer
          tiff TIFF image loader support
          webp WEBP image loader support
          zlib Zlib loader support

          leptonica

          utils Install command-line utilities

          libafterimage

          shaping Use MIT shaped X windows extention.
          shm Use MIT shared memory extention for X image transfer.

          libass

          harfbuzz Enables OpenType shaping via media-libs/harfbuzz.

          libbdplus

          aacs Add support for decryption of AACS

          libbluray

          aacs Add support for decryption of AACS
          bdplus Use media-libs/libbdplus for BD+ decryption
          java Add support for BD-J
          utils Install command-line utilities and examples

          libcanberra

          alsa Enables ALSA sound driver.
          gstreamer Enables gstreamer sound driver. Not useful when alsa or pulseaudio is available.
          gtk Enables building of gtk+ helper library, gtk+ runtime sound effects and the canberra-gtk-play utility. To enable the gtk+ sound effects add canberra-gtk-module to the colon separated list of modules in the GTK_MODULES environment variable.
          gtk3 Enables building of gtk+3 helper library, gtk+3 runtime sound effects and the canberra-gtk-play utility. To enable the gtk+3 sound effects add canberra-gtk-module to the colon separated list of modules in the GTK_MODULES environment variable.
          pulseaudio Enables PulseAudio sound driver that should be able to support positional event sounds. This is the preferred choice for best sound events experience and picked by default if compiled in and possible to use at runtime.
          sound Install x11-themes/sound-theme-freedesktop to get sounds on Gnome and Xfce.
          tdb Enables Trivial Database support for caching purposes.

          libepoxy

          egl Enable EGL support.

          libextractor

          apparmor Enable apparmor support using sys-libs/libapparmor
          archive Enable archive support using app-arch/libarchive
          gsf Enable OLE2 (MS Office) plug-in support using gnome-extra/libgsf
          midi Enable MIDI support through media-libs/libsmf

          libffado

          test-programs Install standalone test programs

          libggi

          vis Enables sparc vis support for libggi

          libgphoto2

          serial Enable serial port support

          libgpod

          gtk Enable ArtworkDB support

          libgroove

          chromaprint Enable audio fingerprinting using media-libs/chromaprint.
          loudness Enable loudness detection according to the EBU R128 standard using media-libs/libebur128.
          sound Enable audio playing.

          liblastfm

          fingerprint Build the lastfm-fingerprint library

          libmp4v2

          utils Install command-line utilities

          libmypaint

          gegl Add support for media-libs/gegl

          libopenglrecorder

          openh264 Enable H.264 support using media-libs/openh264
          vpx Enable VP8/VP9 codec support via media-libs/libvpx

          libpagemaker

          tools Build command line file format conversion tools

          libplacebo

          glslang Use dev-util/glslang to compile GLSL
          lcms Add support for color management via media-libs/lcms
          shaderc Use media-libs/shaderc to compile GLSL
          vulkan Add support for the vulkan graphics API

          libpng

          apng support unofficial APNG (Animated PNG) spec

          libpng-compat

          apng support unofficial APNG (Animated PNG) spec

          libpostproc

          pic Force shared libraries to be built as PIC (this is slower).

          libprojectm

          gles2 Provide support for OpenGL ES 2 and 3

          libsdl

          joystick Control joystick support (disable at your own risk)
          sound Control audio support (disable at your own risk)
          tslib Build with tslib support for touchscreen devices
          video Control video support (disable at your own risk)

          libsdl2

          gles include OpenGL ES support
          haptic Enable the haptic (force feedback) subsystem
          joystick Control joystick support (disable at your own risk)
          kms Build the KMSDRM video driver
          sound Control audio support (disable at your own risk)
          tslib Build with tslib support for touchscreen devices
          video Control video support (disable at your own risk)
          vulkan Enable Vulkan support

          libvisio

          tools Build conversion tools

          libvpx

          highbitdepth Enable 10 and 12 bit support for VP9.
          postproc Enable additional post processing filters
          svc Enable spatial-svc support (experimental)

          libwebp

          swap-16bit-csp Enable byte swapping for 16 bit colorspace

          libyami

          dmabuf Enable dma_buf buffer sharing.
          egl Enable EGL support.
          md5 Add support for generating md5 sums for each frame.
          v4l Add support for V4L2 hardware codecs.

          libzmf

          tools Build conversion tools

          lilv

          dyn-manifest Add LV2 Dynamic Manifest support. See //lv2plug.in/ns/ext/dynmanifest/

          lsp-plugins

          lv2 build lv2 plugins

          lv2

          plugins Enables examples plugins.

          lvtk

          gtk2 Enable x11-libs/gtk+:2 based GUI support
          tools Compile and install ttl2c tool

          mediastreamer

          amr Use of AMR Narrow Band codec plugin
          filters Enable compilation of filters
          g726 Support g726 codec
          g729 Use g726 codec plugin
          ilbc Use of iLBC (RFC3951) codec plugin
          ntp-timestamp Turn on NTP timestamping on received packet
          ortp Enable usage of net-libs/ortp
          pcap Enable usage of net-libs/libpcap
          video Enable video support

          mesa

          classic Build drivers based on the classic architecture.
          d3d9 Enable Direct 3D9 API through Nine state tracker. Can be used together with patched wine.
          dri3 Enable DRI3 support.
          egl Enable EGL support.
          gallium Build drivers based on Gallium3D, the new architecture for 3D graphics drivers.
          gbm Enable the Graphics Buffer Manager for EGL on KMS.
          gles1 Enable GLESv1 support.
          gles2 Enable GLESv2 support.
          libglvnd Use libglvnd for dispatch.
          llvm Enable LLVM backend for Gallium3D.
          opencl Enable the Clover Gallium OpenCL state tracker.
          osmesa Build the Mesa library for off-screen rendering.
          pax_kernel Enable if the user plans to run the package under a pax enabled hardened kernel
          pic disable optimized assembly code that is not PIC friendly
          valgrind Compile in valgrind memory hints
          vdpau Enable the VDPAU acceleration interface for the Gallium3D Video Layer.
          vulkan Enable Vulkan drivers
          vulkan-overlay Build vulkan-overlay-layer which displays Frames Per Second and other statistics
          wayland Enable support for dev-libs/wayland
          xa Enable the XA (X Acceleration) API for Gallium3D.
          xvmc Enable the XvMC acceleration interface for the Gallium3D Video Layer.

          mlt

          compressed-lumas Compress the luma files in png.
          frei0r Build the module for media-plugins/frei0r-plugins
          kdenlive Build support for kde-apps/kdenlive
          lua Build SWIG bindings for Lua
          melt Build the melt commandline tool
          opencv Build motion tracking module using media-libs/opencv
          python Build SWIG bindings for Python
          rtaudio Builds rtaudio consumer for native audio support on multiple platforms.
          ruby Build SWIG bindings for Ruby
          vidstab Enabled video stabilization with media-libs/vidstab.

          netpbm

          rle Build converters for the RLE format (utah raster toolkit)

          opencv

          contrib Install user contributed scripts from opencv_contrib (Experimental!)
          contribcvv CVV module requires Qt5
          contribdnn DNN module contrib requires tiny dnn
          contribhdf HDF module requires sci-libs/hdf5
          contribsfm SFM module requires eigen, gflags, and glog
          contribxfeatures2d Enables xfeatures2d and autodownload of samples in contrib
          cuda Enable NVIDIA Cuda computations support (Experimental!)
          dnnsamples Download dnn caffeemodel samples
          download Enable download during cmake configure
          eigen Enable usage of dev-cpp/eigen for computations
          features2d Enable features2d module
          gdal Enable support for sci-libs/gdal library
          gflags Use Google's C++ argument parsing library
          glog Use Google's C++ loggin library
          opencl Add support for OpenCL
          opencvapps Enable compilation with opencvapps
          tesseract Use Google's OCR Engine
          testprograms Build and install programs for testing OpenCV (performance)
          vtk Build new 3D visualization module viz based on sci-libs/vtk

          openh264

          plugin Install the Gecko Media Plugin (GMP) for use with Mozilla packages
          utils Install the CLI encoder and decoder utilities

          openimageio

          color-management Enable color management via media-libs/opencolorio
          dicom Enable DICOM medical image file support via sci-libs/dcmtk
          field3d Enable f3d file (write) support via media-libs/Field3D
          opencv Enable OpenCV support via media-libs/opencv
          ptex Enable Ptex texture mapping system file support via media-libs/ptex

          opensubdiv

          cuda Enable NVIDIA CUDA Toolkit support through dev-util/nvidia-cuda-toolkit.
          opencl Enable OpenCL support through virtual/opencl.
          ptex Adds support for faster per-face texture mapping through media-libs/ptex.
          tbb Enable multithreading with the Intel Threads Building Blocks through dev-cpp/tbb.

          opus

          custom-modes Enable non-Opus modes, e.g. 44.1 kHz and 2^n frames

          opusfile

          fixed-point Enable fixed-point arithmetic operations
          float Enable floating point arithmetic operations
          http Enable http connections

          osl

          partio Use media-libs/partio
          qt5 Build the osltoy binary

          phonon

          designer Install plugin for dev-qt/designer
          vlc Install VLC Phonon backend

          500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          network Enable network streaming support via libsoup

          portmidi

          test-programs Install various example programs

          qtav

          gui Build a video player gui

          quvi

          json Enable support for JSON output

          raptor

          json Enable support for JSON parsing

          raspberrypi-userland-bin

          hardfp Use armv6 hardfp ABI

          sdl-mixer

          fluidsynth Use media-sound/fluidsynth for MIDI support
          midi basic support for MIDI files
          mod basic support for MOD files
          playtools Install playwave and playmus tools (useful for testing)
          smpeg Use media-libs/smpeg for MP3 support
          wav support WAVE files

          sdl-sound

          physfs Enable support for various formats through dev-games/physfs.

          sdl2-image

          webp support loading WEBP images

          sdl2-mixer

          fluidsynth Use media-sound/fluidsynth for MIDI support
          midi basic support for MIDI files
          mod basic support for MOD files
          playtools Install playwave and playmus tools (useful for testing)
          smpeg Use media-libs/smpeg for MP3 support
          tremor enable OGG Vorbis music via libtremor
          wav support WAVE files

          sge

          image enable sdl-image support

          spandsp

          fixed-point Enable fixed point support

          speex

          utils Enables speex commandline utilities (speexenc, speexdec).
          vbr Enable VBR support.

          svgalib

          kernel-helper Build the helper kernel module

          tremor

          low-accuracy enable 32bit only multiply operations

          urt

          tools Install tools

          vigra

          valgrind Enable valgrind in make check

          vulkan-loader

          layers Include the vulkan layers

          waffle

          egl Enable EGL support
          gbm Enable support for the Generic Buffer Manager (gbm)
          wayland Enable Wayland support

          x264

          interlaced enable interlaced encoding support, this can decrease encoding speed by up to 2%
          opencl Add support for OpenCL.
          pic disable optimized assembly code that is not PIC friendly

          x265

          10bit Add support for producing 10bits HEVC.
          12bit Add support for producing 12bits HEVC.
          numa Build with support for NUMA nodes.
          pic Disable optimized assembly code that is not PIC friendly
          power8 Enable support for Power 8 assembly optimizations.

          xine-lib

          bluray Enable playback of Blu-ray filesystems using media-libs/libbluray
          dxr3 Enable support for DXR3 mpeg acceleration cards.
          flac Build the media-libs/flac based FLAC demuxer and decoder. This flag is not needed for playing FLAC content, neither standalone nor in Ogg container (OggFLAC), but might have better support for exotic features like 24-bit samples or 96kHz sample rates.
          gtk Build the gdkpixbuf-based image decoder plugin.
          imagemagick Build the ImageMagick-based image decoder plugin.
          mad Build the media-libs/libmad based mp3 decoder. This mp3 decoder has superior support compared to the one coming from FFmpeg that is used as a fallback. If you experience any bad behaviour with mp3 files (skipping, distorted sound) make sure you enabled this USE flag.
          mmap Use mmap() function while reading file from local disks. Using mmap() will use more virtual memory space, but leaves to the Kernel the task of caching the file's data. mmap() access should be faster, but might misbehave if the device where the file resides in is removed during playback.
          truetype Use media-libs/freetype for font rendering and media-libs/fontconfig for font discovery. Enabling this USE flag will allow OSD (such as subtitles) to use more advanced font and to more easily select which font to use. The support for TrueType fonts in xine-lib is still experimental, and might not be as good looking as the bitmap fonts used with this USE flag disabled.
          vdr Build the VDR plugin
          vidix Enable support for vidix video output.
          vis Adds support for SIMD optimizations for UltraSPARC processors.
          vpx Enable VP8 codec support via media-libs/libvpx.
          xvmc Enable support for XVideo Motion Compensation (accelerated mpeg playback).

          xvid

          pic disable optimized assembly code that is not PIC friendly

          zita-resampler

          tools Install zresample and zretune tools

          media-plugins

          alsa-plugins

          arcam_av Enables Arcam AV control plugin
          mix Enables upmix and vdownmix plugin
          usb_stream Enables usb_stream plugin

          audacious-plugins

          adplug Build with AdPlug (Adlib sound card emulation) support
          ampache Support controlling audacious via www-apps/ampache
          bs2b Enable Bauer Bauer stereophonic-to-binaural headphone filter
          cue Support CUE sheets using the libcue library
          fluidsynth Support FluidSynth as MIDI synth backend
          gme Support various gaming console music formats
          gtk Build with GTK interface instead of Qt5
          http Support HTTP streams through neon
          qt5 Build with Qt5 interface instead of GTK
          qtmedia Enable playback via dev-qt/qtmultimedia
          scrobbler Build with scrobbler/LastFM submission support
          sid Build with SID (Commodore 64 Audio) support
          soxr Build with SoX Resampler support
          speedpitch Enable speed/pitch effects
          streamtuner Build the streamtuner plugin

          calf

          experimental Enable experimental features/plugins
          lv2 Add support for Ladspa V2

          frei0r-plugins

          facedetect Enables building of facedetect plugin, which depends on media-libs/opencv
          scale0tilt 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          threads Use separate thread to init connection (unsafe)

          grilo-plugins

          chromaprint Enable Chromaprint support
          daap Enable dmap support through net-libs/libdmapsharing
          flickr Enable Flickr support
          freebox Build support for viewing TV channels using Freebox
          gnome-online-accounts Enable net-libs/gnome-online-accounts support
          thetvdb Build support for thetvdb.com
          tracker Build support for content discovery using the app-misc/tracker indexer
          youtube Build support for YouTube content discovery using dev-libs/libgdata

          gst-plugins-gtk

          egl Enable EGL platform usage
          gles2 Enable gtkglsink OpenGL sink based on GLESv2 API
          opengl Enable gtkglsink OpenGL sink based on desktop OpenGL API

          gst-plugins-libav

          libav Use bundled ffmpeg to support systems using media-video/libav globally instead of media-video/ffmpeg

          gst-plugins-meta

          http Enable http streaming via net-libs/libsoup
          libvisual Enable visualization effects via media-libs/libvisual
          vpx Enables vp8 codec support using libvpx, required to play some HTML5 videos

          gst-plugins-vaapi

          drm Enable DRM renderer
          egl Enable EGL support
          gles2 Enable GLESv2 and GLESv3 support

          hexter

          gtk2 Enable x11-libs/gtk+:2 based GUI

          imlib2_loaders

          eet Enable Eet image loader
          xcf Enable XCF image loader

          mediastreamer-ilbc

          20ms-frames enable 20ms frame size (default is 30ms). Some VOIP providers such as Gizmo5 (aka Sipphone) require the codec to be compiled with the 30ms setting.

          mythplugins

          cdr Allows MythMusic to burn CD-Rs
          exif Allows MythGallery to read EXIF data from photos
          fftw Adds visual effects to MythMusic when playing back music
          hls HTTP Live Streaming support
          mytharchive Allows you to archive recorded content to CD or DVD
          mythbrowser Adds a web browser within MythTV
          mythgallery Adds a picture viewing gallery within MythTV
          mythgame Adds a frontend to various ROM emulators within MythTV
          mythmusic Adds the ability for MythTV to act as a music player
          mythnetvision Adds the ability to view netvision devices within MythTV
          mythnews Adds a news viewer within MythTV
          mythweather Adds weather information within MythTV
          mythzmserver Build mythzmserver daemon needed by zoneminder on LAN
          mythzoneminder Adds support for zoneminder (requires active mythzmserver daemon on LAN).
          raw Allows MythGallery to view photos saved in RAW format

          vdr-burn

          dvdarchive DMH DVD - Archive

          vdr-cdplayer

          cdparanoia Enable cdparanoia (audio CD ripper) support

          vdr-dvbapi

          dvbcsa use media-libs/libdvbcsa free implementation of the DVB Common Scrambling Algorithm

          vdr-epgsearch

          conflictcheckonly install the "conflictcheckonly" vdr-plugin
          epgsearchonly install the "epgsearchonly" vdr-plugin
          quicksearch install the "quicksearch" vdr-plugin
          tre Add support for unlimited fuzzy searching with help of dev-libs/tre library

          vdr-streamdev

          client Compile the VDR plugin vdr-streamdev-client that acts like a dvb-budget card
          server Compile the VDR plugin vdr-streamdev-server that allows remote systems to access the DVB cards used for the local VDR

          vdr-vdrmanager

          stream Add support for streaming Video to Android client

          vdr-weatherng

          dxr3 enables lower osd color depth for dxr3 cards

          vdr-xineliboutput

          bluray Enable BluRay metadata support through media-libs/libbluray
          cec Enable CEC support through dev-libs/libcec
          libextractor Use media-libs/libextractor to gather files' metadata in media-player
          vdr Compile the vdr output plugin to use local or remote xine as output
          xine Compile the xine input plugin for displaying vdr video and OSD

          media-radio

          ax25-tools

          X Enable some X based configuration tools.

          fldigi

          hamlib Enables support by the Hamlib amateur radio rig control library to get/set frequency and mode of the ham radio in use

          tucnak

          hamlib Enables support by the Hamlib amateur radio rig control library to get/set frequency and mode of the ham radio

          unixcw

          ncurses Enables building the curses based morse code tutor program 'cwcp'.

          xastir

          gdal Support for some further map formats
          geotiff Install geotiff support. Allows using USGS DRG topo maps or other types of geotiff mapes/images

          media-sound

          abcde

          aiff Enable support for Audio Interchange File Format (AIFF) output encoding
          id3tag Support ID3, ID3v2 tagging of audio files
          mac Enable support for Monkey's Audio files
          normalize Add support for normalizing audio file volume levels
          replaygain Support for Replay Gain metadata, for relative volume adjustment

          abcm2ps

          pango Use the pango library to render fonts with non-latin characters

          alsa-utils

          bat install basic audio tester (BAT) util
          libsamplerate install utils that use libsamplerate (e.g. alsaloop)
          ncurses install utils that use ncurses (e.g. alsamixer)

          alsaplayer

          id3tag Enables ID3 tagging with id3tag library

          amsynth

          dssi Enable support for DSSI Soft Synth Interface
          lv2 Add support for Ladspa V2

          apulse

          sdk Install PulseAudio headers and pkg-config files. Be aware apulse is not a full PulseAudio replacement by design and some functionality may be missing.

          aqualung

          ifp Enable support for iRiver iFP portable audio players
          lua Enable support for programmable title formatting with dev-lang/lua
          mac Enable support for decoding Monkey's Audio files
          podcast Enable podcast support
          systray Enable system tray support

          ario

          idle Enable experimental support for MPD's idle command to reduce bandwidth and cpu usage, requires MPD 0.14
          scrobbler Enable audioscrobbler/last.fm support net-libs/libsoup

          asunder

          mac Support for creation of Monkey's Audio files (APE)

          audacious

          gtk Build with GTK interface instead of Qt5
          qt5 Build with Qt5 interface instead of GTK

          audacity

          id3tag Enables ID3 tagging with id3tag library
          lv2 Add support for Ladspa V2
          midi Enables MIDI support
          portmixer Enable the internal portmixer feature
          sbsms Enables sbsms library support for slower, more accurate pitch and tempo changing
          soundtouch Enables soundtouch library support for pitch and tempo changing
          twolame Enables twolame support (MPEG Audio Layer 2 encoder)
          vamp Enables vamp plugins support (Audio analysing plugins)
          vst Enable VST plugin support

          audiotools

          cue Enable CUE sheet support
          dvda Enable DVD-Audio support
          gui Enable support for GUI tools
          twolame Enable twolame support (MPEG Audio Layer 2 encoder)

          beets

          badfiles Validate MP3 & FLAC files
          chromaprint Enable support for acoustic fingerprinting plugin using media-libs/chromaprint
          discogs Enable support for the discogs API plugin
          ffmpeg Enable support for the convert plugin to transcode files via media-video/ffmpeg
          lastfm Enable support for importing personal last.fm playcounts and music genres from last.fm tags
          mpd Enable support for media-sound/mpd server emulation and statistic gathered from media-sound/mpd
          replaygain Enable support for Replay Gain metadata calculation during import
          thumbnail Enable album thumbnails generation
          webserver Enable embedded webserver support through dev-python/flask

          bluez-alsa

          hcitop Enable top-like monitoring tool for HCI
          ldac Enable support for AOSP media-libs/libldac dispatcher
          ofono Enable ofono elephony support

          cadence

          a2jmidid Enables support for legacy ALSA sequencer applications in JACK MIDI system

          cantata

          cdio Use dev-libs/libcdio-paranoia for CD support (instead of cdparanoia)
          http-server Enable internal HTTP server to play non-MPD files
          replaygain Enable ReplayGain support, for relative volume adjustments
          streaming Enable playback of MPD HTTP streams using LibVLC (media-video/vlc)

          clementine

          box Enable filesharing via Box.com
          dropbox Enable Dropbox support
          googledrive Enable Google Drive support
          lastfm Use liblastfm for fetching song info, scrobbling and radio streams
          moodbar Enable moodbar support
          projectm Build with ProjectM visualization
          seafile Enable support for seafile: a file sync service
          skydrive Enable Skydrive support
          wiimote Enable support for Wii remote

          cmus

          cdio Use libcdio for CD support
          cue Enable CUE sheet parsing
          discid Enable reading the ID of the inserted CD
          elogind Enable MPRIS support via sys-auth/elogind
          pidgin Install support script for net-im/pidgin
          systemd Enable MPRIS support via sys-apps/systemd
          tremor Use libivorbis from media-libs/tremor instead of media-libs/libvorbis

          csound

          beats Build the beats score frontend
          chua Build the chua opcodes
          csoundac Build the CsoundAC extension module
          double-precision Use double-precision floating point for audio samples
          dssi Build the DSSI opcodes
          fluidsynth Build the fluidsynth opcodes
          image Build the image opcodes
          keyboard Build Virtual MIDI keyboard
          linear Build the linear algebra Opcodes
          portmidi Build the PortMIDI I/O module
          samples Install the HRTF datafiles for use with hrtfmove, hrtfmove2, hrtfstat, hrtfearly, and hrtfreverb
          score Build the alternative score parser
          stk Build the stk opcodes
          tcl Build the tcl interface and clients
          utils Build stand-alone executables for utilities that can also be used via `csound -U`
          websocket Build the websocket opcode

          darkice

          aacplus AAC+ encoding via media-libs/libaacplus
          twolame Build with twolame support

          deinvert

          liquid improve sound quality using net-libs/liquid-dsp
          wav wav file support using media-libs/libsndfile

          denemo

          alsa Enable alsa support through media-libs/alsa-lib
          aubio Enable media-libs/aubio support
          doc Use dev-util/gtk-doc to build documentation in html format
          evince Use app-text/evince document viewer
          fluidsynth Enable Fluidsynth MIDI software synthesis using media-sound/fluidsynth
          gtk3 Enable support for the GTK+. If enabled uses slot 3 of x11-libs/gtk+, if disabled it uses slot 2
          500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          Enable jack support through virtual/ 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          portaudio Enable support for media-libs/portaudio
          portmidi Enable support for the media-libs/portmidi backend
          rubberband Enable support for media-libs/rubberband

          dir2ogg

          mac Add support for decoding Monkey's Audio files
          wma Add support for wma files through mplayer

          drumstick

          fluidsynth Enable support for media-sound/fluidsynth

          easytag

          nautilus Build gnome-base/nautilus extension

          ecasound

          lv2 Add support for Ladspa V2
          oil Use dev-libs/liboil for inner loop optimizations

          elisa

          mpris Enable MPRIS support
          vlc Use media-video/vlc for output rather than dev-qt/qtmultimedia

          exaile

          scrobbler Enable audioscrobbler/last.fm support

          fapg

          xspf Enable support for saving XSPF playlists.

          gimmix

          cover Enable cover art fetching
          lyrics Enable lyric fetching

          gmpc

          unique Enable single instance support using dev-libs/libunique
          xspf Enable support for reading and saving XSPF playlists

          gmusicbrowser

          extras Install some extra deps for plugins (ex. Titlebar)

          guitarix

          lv2 Build lv2 plugins
          standalone Build standalone application

          herrie

          http Enable http streaming
          xspf Enable support for reading and saving XSPF playlists

          hydrogen

          archive Use libarchive instead of libtar
          portmidi Add portmidi support

          500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          -audio-connection-kit
          pam Add basic realtime configuration via sys-auth/realtime-base

          500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          2
          classic Enable building of 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          d
          metadata Enable metadata API
          pam Add basic realtime configuration via sys-auth/realtime-base

          jalv

          gtk2 Adds support for GTK+2 in addition to GTK+3 controlled by the gtk useflag.
          gtkmm Adds support for dev-cpp/gtkmm: C++ interface for GTK+2

          kid3

          acoustid Build acoustic fingerprinting plugin using media-libs/chromaprint
          mpris Enable support for MPRIS2 interface using dev-qt/qtdbus

          klick

          rubberband Enable rubberband support

          lame

          frontend Build and install the 'lame' executable frontend to lame libraries.
          mp3rtp Build the mp3-to-RTP streaming utility. **UNSUPPORTED**

          lilypond

          guile2 Enable experimental support for Guile 2

          linuxsampler

          lv2 Add support for Ladspa V2
          sf2 Add support for SoundFont 2 sound bank files

          lmms

          fluidsynth Enables Fluidsynth MIDI software synthesis plugin.
          libgig Enables GIG player plugin.
          soundio Enables libsoundio support.
          stk Enables STK Mallet plugin.
          vst Enables the VeSTige plugin to run VST plugins through Wine.

          loudness-scanner

          mpg123 build the mpg123 plugin
          musepack build the musepack plugin
          sndfile build the sndfile plugin

          lyvi

          mpris Enable MPRIS support

          mangler

          espeak Text to speech engine
          g15 Logitech g15 lcd support

          mixxx

          hid Enable HID controller support
          lv2 Add support for Ladspa V2 via media-libs/lilv
          shout Enable broadcasting support via media-libs/libshout

          moc

          cache Enable tags caching support
          sid Build with SID (Commodore 64 Audio) support
          tremor Build vorbis support using an integer implementation of the vorbis library (media-libs/tremor)

          mp3blaster

          sid Build with SID (Commodore 64 Audio) support

          mpd

          adplug Enable the AdPlug decoder plugin
          cdio Use libcdio for ISO9660 parsing support
          chromaprint Enable ChromaPrint / AcoustID support
          cue Enable CUE sheet support
          curl Support for web stream listening
          eventfd Use the eventfd function in MPD's event loop
          faad Use external faad library for AAC decoding
          fifo Support writing audio to a FIFO
          fluidsynth Enables Fluidsynth MIDI software synthesis (discouraged)
          gme Enables support for media-libs/game-music-emu for playing various video game music formats.
          id3tag Support for ID3 tags
          inotify Use the Linux kernel inotify subsystem to notice changes to mpd music library
          lame Support for MP3 streaming via Icecast2
          libmpdclient Enable support for remote mpd databases
          libsoxr Enable the libsoxr resampler
          mpg123 Enable support for mp3 decoding over media-sound/mpg123
          network Enables network streaming support
          nfs Enable support for the Network File System
          pipe Support writing audio to a pipe
          qobuz Build plugin to access qobuz
          recorder Enables output plugin for recording radio streams
          sid Build with SID (Commodore 64 Audio) support
          signalfd Use the signalfd function in MPD's event loop
          soundcloud Build plugin to access soundcloud
          systemd Enable support for systemd socket activation
          tidal Build plugin to access tidal
          twolame Support twolame MPEG-2 encoding
          webdav Enable using music from a WebDAV share
          wildmidi Enable MIDI support via wildmidi

          mpfc

          wav Enable wav audio codec support

          mpg123

          int-quality Use rounding instead of fast truncation for integer output, where possible

          mumble

          g15 Enable support for the Logitech G15 LCD (and compatible devices).
          rnnoise Enable alternative noise suppression option based on RNNoise.
          speech Enable text-to-speech support in Mumble.

          murmur

          ice Use dev-libs/Ice to enable remote control capabilities.

          musescore

          portmidi Enable support for building against media-libs/portmidi
          vorbis Enable SoundFont support using media-libs/libvorbis
          webengine Use dev-qt/qtwebengine for embedded web browser

          ncmpc

          async-connect Enable asynchronous connect
          chat-screen Enable the chat screen
          help-screen Enable the help screen
          key-screen Enable key editor screen
          library-screen Enable library screen
          lyrics-screen Enable lyrics screen
          mouse Enable curses getmouse support
          outputs-screen Enable the outputs screen
          search-screen Enable search screen
          song-screen Enable song viewer screen

          ncmpcpp

          clock Enable clock screen
          outputs Enable outputs screen
          visualizer Enable visualizer screen with sound wave/frequency spectrum modes

          patchage

          500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          -dbus
          Use Jack via D-Bus instead of lib 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          session Include experimental Jack session management (save/restore) support

          pithos

          appindicator Enable usage of appindicator to export menu options in to unity
          keybinder Use keybinder to enable global key bindings

          pms

          regex Enable regular expression searches

          pragha

          glyr Enable music metadata searchengine support using media-libs/glyr
          grilo Play songs on DLNA servers using media-libs/grilo
          keybinder Enable shortcut support using dev-libs/keybinder
          koel Append music on Koel server
          lastfm Enable last.fm support using media-libs/libclastfm
          peas Enable various plugins that will pull in dev-libs/libpeas as a dependency
          playlist Enable enhanced playlist support using dev-libs/totem-pl-parser
          rygel Share music on DLNA using net-misc/rygel
          soup Search metadata on AcoustID and radios on TuneIn using net-libs/libsoup

          pulseaudio

          X Build the X11 publish module to export PulseAudio information through X11 protocol for clients to make use. Don't enable this flag if you want to use a system wide instance. If unsure, enable this flag.
          alsa-plugin Request installing media-plugins/alsa-plugins with PulseAudio plugin enabled. This ensures that clients supporting ALSA only will use PulseAudio.
          asyncns Use libasyncns for asynchronous name resolution.
          doc Build the doxygen-described API documentation.
          elogind Use sys-auth/elogind for giving each session a PA client
          equalizer Enable the equalizer module (requires sci-libs/fftw).
          gconf Ensure gnome-base/gconf is present for pulseaudio GConf to GSettings module automatic migration (keeping the user configuration)
          gdbm Use sys-libs/gdbm to store PulseAudio databases. Recommended for desktop usage. This flag causes the whole package to be licensed under GPL-2 or later.
          glib Add support to dev-libs/glib-based mainloop for the libpulse client library, to allow using libpulse on glib-based programs. Build the GSettings PA module.
          native-headset Build with native HSP backend for bluez 5.
          ofono-headset Build with oFono HFP backend for bluez 5, requires net-misc/ofono.
          oss Enable OSS sink/source (output/input). Deprecated, upstream does not support this on systems where other sink/source systems are available (i.e.: Linux). The padsp wrapper is now always build if the system supports OSS at all.
          realtime Makes PulseAudio use RealtimeKit (sys-auth/rtkit) to get real-time priority while running.
          ssl Use dev-libs/openssl to provide support for RAOP (AirPort) streaming.
          system-wide Allow preparation and installation of the system-wide init script for PulseAudio. Since this support is only supported for embedded situations, do not enable without reading the upstream instructions at //www.freedesktop.org/wiki/Software/PulseAudio/Documentation/User/WhatIsWrongWithSystemWide/ .
          systemd Build with sys-apps/systemd support to replace standalone ConsoleKit.
          webrtc-aec Uses the webrtc.org AudioProcessing library for enhancing VoIP calls greatly in applications that support it by performing acoustic echo cancellation, analog gain control, noise suppression and other processing.

          pulseeffects

          bs2b Enable use of media-libs/libbs2b
          calf Enable use of media-plugins/calf for adding various FX
          mda-lv2 Enable use of media-plugins/mda-lv2 for the loudness FX
          rubberband Enable usse of media-libs/rubberband for the pitch shifting FX

          qmidiarp

          lv2 Enables Ladspa V2 plugins.

          qmmp

          analyzer Enable visual analyzer
          archive Enable archiving plugin via app-arch/libarchive.
          bs2b Enable Bauer stereophonic-to-binaural headphone filter
          cover Enable album cover support
          crossfade Enable crossfade effect when switching tracks
          cue enable CUE sheet parsing
          dbus Enable DBus notifiications and MPRIS support
          enca Detects the character encoding automatically
          game Enable Game music support
          gnome Enable Gnome hotkey support (requires Qt5DBus)
          lyrics Fetch track lyrics from the web
          midi Enable midi support using wildmidi library
          notifier Enable qmmps' notifier system
          projectm Enable projectm music visualization plugin
          qsui Enable QMMP simple UI
          qtmedia Enable playback via dev-qt/qtmultimedia
          scrobbler Enable audioscrobbler/last.fm support
          shout Enable shoutcast plug-in via media-libs/libshout.
          sid Build with SID (Commodore 64 Audio) support
          sndfile Enable wav playback support via media-libs/libsndfile
          soxr Use the SoX resampling library
          stereo Enable stereo effect
          tray Build tray icon

          qsampler

          libgig Enable libgig support for loading Gigasampler files and DLS (Downloadable Sounds) Level 1/2 files

          qtractor

          aubio Enable media-libs/aubio support
          dssi Enable support for DSSI Soft Synth Interface
          rubberband Enable support for in-place audio clip pitch-shifting through the rubberband library

          rhythmbox

          daap Build the local network music sharing plugin which uses the DAAP protocol using net-libs/libdmapsharing

          shntool

          alac Add support for Apple Lossless Audio Codec files
          mac Add support for Monkey's Audio files
          shorten Add support for the shorten audio compressor

          snapcast

          client Build and install Snapcast client component
          server Build and install Snapcast server component
          tremor Build with TREMOR version of vorbis

          snd

          s7 Enable the s7 extension language (a version of Scheme)

          sonata

          lyrics Support for lyrics fetching

          sonic-visualiser

          id3tag Enables ID3 tagging with id3tag library

          sox

          amr Enables Adaptive Multi-Rate Audio support
          id3tag Enables ID3 tagging with id3tag library
          twolame Enables twolame support (MPEG Audio Layer 2 encoder)

          split2flac

          enca Try to guess the charset using enca
          flake Add support for Flake, alternative FLAC encoder
          mac Add support for Monkey's Audio files
          replaygain Support for Replay Gain metadata, for relative volume adjustment

          spotify

          pax_kernel Triggers a paxmarking of the main Spotify binary
          systray Pulls in dependencies needed for systray support on some desktop environments

          supercollider

          emacs Enable the SCEL user interface
          gedit Enable the SCED user interface
          gpl3 Build GPL-3 licensed code (recommended)
          server Build with internal server
          vim Enable the SCVIM user interface

          teamspeak-server

          tsdns Install TeamSpeaks own DNS service for handling multiple virtual servers.

          tomahawk

          telepathy Enable support for the real-time communication framework telepathy

          traverso

          lv2 Add support for Ladspa V2

          umurmur

          mbedtls Use net-libs/mbedtls as TLS provider
          shm Enable shared memory support

          upmpdcli

          thirdparty Enable streaming from Qobuz and Tidal external services

          vimpc

          boost Use boost instead of C++11 libraries

          vorbis-tools

          kate Adds support for Ogg Kate subtitles via libkate.
          ogg123 Build ogg123 player, needs libao and curl

          wildmidi

          player Install the wildmidi player

          xmms2

          airplay Support for airplay format
          asf Support for Monkey's Audio (APE) format with help of bundled libasf
          fluidsynth Enable fluidsynth support (MIDI)
          ices Icecast source output plugin
          mac Support for Monkey's Audio (APE) format with help of media-sound/mac
          mlib-update Enable building of xmms2-mlib-updater client
          ofa 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          phonehome This client sends anonymous usage-statistics to the xmms2
          server Build xmms2 player daemon (otherwise only clients are built)
          sid Support for C64 SID
          valgrind Run unit tests under valgrind.
          vocoder Phase vocoder effect plugin
          xml Enable support for various XML based playlists and sources: RSS, XSPF

          xnoise

          lastfm Enable support for lastfm cover art fetching and scrobbling
          lyrics Enable support for lyrics fetching

          xwax

          alsa Adds support for ALSA audio input/output.
          cdda Sets runtime dependencies to support decoding audio from a compact disc.
          fallback Sets runtime dependencies to support decoding "other" audio files.
          500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          Adds support for audio input/output via the JACK Audio Connection Kit.
          mp3 Sets runtime dependencies to support decoding MP3 audio.
          oss Adds support for OSS (open sound system) audio input/output.

          yarock

          mpv Enable media-video/mpv backend
          phonon Enable media-libs/phonon backend
          vlc Enable media-video/vlc backend

          yoshimi

          lv2 Add support for Ladspa V2

          zynaddsubfx

          dssi Enable support for DSSI Soft Synth Interface

          media-tv

          gentoo-vdr-scripts

          nvram Add support for using nvram-wakeup to set wakeup time in bios

          kodi

          airplay enable AirPlay support
          bluray Enable playback of Blu-ray filesystems
          cec Enable support for HDMI-CEC devices via libcec
          dvd Enable optical (CD/DVD drive) support
          gbm Use the Graphics Buffer Manager for EGL on KMS.
          gles Enable support for GLES
          libusb Use virtual/libusb for usb device hotplug support. This flag should only be enabled if you're running a non-Linux kernel or you don't want to use sys-fs/udev.
          lirc Enable support for controlling Totem with a remote control using app-misc/lirc
          mariadb Add MariaDB support
          nfs Enable NFS client support
          raspberry-pi Enable support for the Raspberry Pi
          system-ffmpeg Use system ffmpeg instead of the bundled one
          udev Use sys-fs/udev rules to handle devices' permissions and hotplug support. Unless you know what you're doing do not disable this flag on Linux kernels. This is provided as an option for completeness.
          webserver Enable internal webserver
          xslt Enable XSLT support using dev-libs/libxslt

          linuxtv-dvb-apps

          alevt Build videotext decoder

          mythtv

          alsa Allows MythTV to directly output sound to ALSA devices
          asi Support for DVEO ASI recorder
          autostart Use a custom autostart configuration
          bluray Use the system libbluray for BluRay support
          cec Allows control of CEC enabled TVs via HDMI
          ceton Ceton InfiniTV 4 a CableCARD-enabled tuner support
          debug Instructs Qt to use the 'debug' target
          egl EGL video output support
          fftw Support visualizations via sci-libs/fftw
          hdhomerun Silicondust USA Inc.network-attached tuner support
          hdpvr Hauppauge HD-PVR?
          hls HTTP Live Streaming support
          ieee1394 Firewire enabled Cable boxe support
          ivtv Support kernel driver for the iTVC15 family of MPEG codecs
          500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          Allows MythTV to use JACK as your sound output device
          java BD-J support for Blu-ray discs
          lcd Enable use of app-misc/lcdproc data display
          lirc LIRC remote control device support
          mythlogserver Enable support for syslog and file logging
          perl Build the perl bindings for MythTV
          vbox V@Box Communications network-attached tuner devices support
          vpx Enable VP8/VP9 support for media-libs/libvpx
          wrapper Use Ubuntu mythtfrontend wrapper
          x265 Enable h265 encoding using x265
          xmltv Support media-tv/xmltv TV listing - not used by Schedules Direct]
          xnvctrl External XNVCtrl support using Nvidia proprietary driver

          tvheadend

          capmt Enable support for capmt (dvbapi) protocol
          constcw Enable support for the constcw protocol
          cwc Enable support for the cwc (newcamd) protocol
          ddci Enable support for DDCI hardware
          dvbcsa Enable decryption of the DVB Common Scrambling Algorithm
          dvben50221 Enable support for hardware CAM
          hdhomerun Enable support for the HDHomeRun device
          imagecache Enable support for image caching
          iptv Enable support for Internet Protocol TV
          satip Enable support for IP-based Satellite TV
          timeshift Enable TimeShift support
          uriparser Use dev-libs/uriparser
          vpx Enable transcoding with the VP8/VP9 video codecs
          x264 Enable transcoding with the H.264 video codec
          x265 Enable transcoding with the HEVC video codec
          xmltv Use media-tv/xmltv

          v4l-dvb-saa716x

          firmware Install firmware

          v4l-utils

          bpf Enables support for IR BPF decoders.

          xmltv

          ar Argentina tv listing grabber
          ch-search Grabber for Switzerland
          dk Denmark tv listing grabber
          dtvla Latin America digital tv listing grabber
          es-laguiatv Spain alternative grabber
          eu-dotmedia Grabber for Europe (xmltv.se / dotmedia)
          eu-epg EPG grabber for some European countries.
          fi Finland tv listing grabber
          fi-sv Grabber for Finland (Swedish)
          fr France tv listing grabber
          fr-kazer France (Kazer) tv listing grabber
          huro Hungarian tv listing grabber
          il Israel tv listing grabber
          is Iceland tv listing grabber
          it Italy tv listing grabber
          na-dd North America tv listing grabber
          na-dtv North America Direct TV grabber
          na-tvmedia Grabber for North America (TVMedia)
          nl Netherlands tv listing grabber
          no-gf Norway Gfeed tv listing grabber
          pt-meo Grabber for Portugal (MEO)
          se-swedb Sweden tv listing grabber
          se-tvzon Sweden (tvzon.se) tv listing grabber
          tr Turkey (Digiturk) tv listing grabber
          tv-check enable GUI checking
          tv-combiner enable grabbers combiner
          tv-pick-cgi enable CGI support
          uk-bleb Britain tv listing grabber
          uk-tvguide UK and Ireland tv listing grabber using TV Guide website
          zz-sdjson Grabber for schedulesDirect.org SD-JSON service (many countries)

          media-video

          aegisub

          uchardet Enable charset discovery via app-i18n/uchardet

          aravis

          fast-heartbeat Enable faster heartbeat rate.
          gstreamer Build the GStreamer plugin.
          packet-socket Enable packet socket support.
          viewer Build the GTK+-based video viewer.

          avidemux

          nvenc Adds support for NVIDIA Encoder (NVENC) API for hardware accelerated encoding on NVIDIA cards.

          chaplin

          transcode Enable DVD ripping and transcoding

          clive

          clipboard Support reading from X clipboard
          pager Support pager!?
          password Support password controlled sites

          dv2sub

          kino install kino plugin

          dvdrip

          fping Enables fping support for cluster rendering
          subtitles Enables support for subtitle ripping

          ffdiaporama

          openclipart Support openclipart database
          texturemate Install extra backgrounds

          ffmpeg

          amr Enables Adaptive Multi-Rate Audio support
          amrenc Enables Adaptive Multi-Rate Audio encoding support with media-libs/vo-amrwbenc.
          appkit Enables Apple AppKit framework
          bluray Enable playback of Blu-ray filesystems
          bs2b Enables media-libs/libbs2b based Bauer stereo-to-binaural filter.
          cdio Enables audio CD grabbing with dev-libs/libcdio.
          chromaprint Enables audio fingerprinting support with media-libs/chromaprint.
          chromium Builds libffmpeg.so to enable media playback in Chromium-based browsers like Opera and Vivaldi.
          codec2 Enables codec2 low bit rate speech codec support via media-libs/codec2.
          cpudetection Enables runtime CPU detection (useful for bindist, compatibility on other CPUs)
          cuda Enables CUDA-based acceleration. Mostly used for specific filters.
          dav1d Enables AV1 decoding via media-libs/dav1d.
          fdk Use external fdk-aac library for AAC encoding
          flite Adds a text-to-speech filter based on app-accessibility/flite.
          frei0r Enable frei0r wrapping in libavfilter
          fribidi Enables fribidi support in the drawtext filter.
          gcrypt Enables gcrypt support: Needed for rtmp(t)e support if openssl, librtmp or gmp is not used.
          gme Enables support for media-libs/game-music-emu for playing various video game music formats.
          gpl Build GPL code. Should be enabled unless you require LGPL binaries.
          hardcoded-tables Use pre-calculated tables rather than calculating them on the fly.
          iec61883 Support for FireWire DV/HDV input device using media-libs/libiec61883.
          kvazaar Enables media-libs/kvazaar based HEVC encoder.
          libaom Enables media-libs/libaom based AV1 codec support.
          libaribb24 Enables ARIB text and caption decoding via media-libs/aribb24.
          libdrm Enables x11-libs/libdrm support for better screen grabbing and hardware accelerated codecs.
          libilbc Enables iLBC de/encoding via media-libs/libilbc.
          librtmp Enables Real Time Messaging Protocol using librtmp (media-video/rtmpdump) in addition to FFmpeg's native implementation.
          libsoxr Enables audio resampling through media-libs/soxr.
          libtesseract Enables the OCR filter via app-text/tesseract.
          libv4l Uses media-libs/libv4l for video4linux instead of direct calls. Adds support for more devices via the userspace library.
          libxml2 Uses dev-libs/libxml2 to enable dash demuxing support.
          lv2 Enables lv2 audio filter wrapper.
          mipsdspr1 Enables MIPS DSP ASE R1 optimizations.
          mipsdspr2 Enables MIPS DSP ASE R2 optimizations.
          mipsfpu Enables floating point MIPS optimizations.
          mmal Enables Multi-Media Abstraction Layer (MMAL) decoding support: Available e.g. on the Raspberry Pi.
          network Enables network streaming support
          nvenc Adds support for NVIDIA Encoder (NVENC) API for hardware accelerated encoding on NVIDIA cards.
          opencl Enable OpenCL support
          openh264 Enables H.264 encoding suppoprt via media-libs/openh264.
          openssl Enables dev-libs/openssl support. Adds support for encrypted network protocols (TLS/HTTPS).
          pic Force shared libraries to be built as PIC (this is slower)
          postproc Build and install libpostproc.
          rubberband Adds time-stretching and pitch-shifting audio filter based on media-libs/rubberband.
          snappy Enable app-arch/snappy support. Required for e.g. Vidvox Hap encoder.
          srt Enable support for Secure Reliable Transport (SRT) via net-libs/srt
          ssh Enable SSH/sftp support via net-libs/libssh.
          twolame Enables MP2 encoding via media-sound/twolame as an alternative to the internal encoder.
          vidstab Enables video stabilization filter using vid.stab library (media-libs/vidstab).
          vpx Enables vp8 codec support using libvpx: Decoding vp8 does not require this to be enabled but libvpx can also be used for decoding; encoding vp8 requires this useflag to be enabled though.
          x265 Enables HEVC encoding with media-libs/x265.
          zeromq Enables net-libs/zeromq support with the zmq/azmq filters.
          zimg Enables media-libs/zimg based scale filter.
          zvbi Enables media-libs/zvbi based teletext decoder.

          ffmpeg2theora

          kate Adds support for Ogg Kate subtitles via libkate.

          google2srt

          html Install HTML documentation

          guvcview

          qt5 Build with Qt5 interface instead Gtk+

          h264enc

          ogm Support for OGM container format

          handbrake

          fdk Support for encoding AAC using media-libs/fdk-aac.
          gstreamer Support for the streaming media framework from media-libs/gstreamer.
          gtk Install the GTK UI, ghb.
          libav-aac Support for encoding AAC using media-video/libav's internal encoder.
          numa Adds support for x265's NUMA capabilities.
          nvenc Adds support for NVIDIA Encoder (NVENC) API for hardware accelerated encoding on NVIDIA cards.
          x265 Support for encoding h265 using media-libs/x265.

          kino

          gpac Enable GPAC support when exporting to 3GPP format

          kmplayer

          npp Compile the npp backend that plays xembed style browser plugins.

          libav

          aac Use external vo-aacenc library for AAC encoding
          amr Enable Adaptive Multi-Rate Audio support
          armv5te Enable optimizations for armv5te processors
          armv6 Enable optimizations for armv6 processors
          armv6t2 Enable optimizations for armv6t2 processors
          armvfp Enable VFP optimizations for ARM processors
          bs2b Enable media-libs/libbs2b based Bauer stereo-to-binaural audio filter
          cdio Enable audio CD grabbing with dev-libs/libcdio.
          cpudetection Enables runtime CPU detection (useful for bindist, compatibility on other CPUs).
          faac Use external faac library for AAC encoding
          fdk Use external fdk-aac library for AAC encoding and decoding
          frei0r Enable frei0r wrapping in libavfilter
          gpl Build all GPL licensed code. Without this flag set the package is build under LGPL license.
          hardcoded-tables Use pre-calculated tables rather than calculating them on the fly.
          network Enable network streaming support.
          nvidia Enable nvidia video codec hardware acceleration support.
          openssl Prefer dev-libs/openssl over net-libs/gnutls to provide SSL/TLS support (notice: the resulting binaries are unredistributable).
          opus Use the external opus library for encoding and decoding.
          pic Force shared libraries to be built as PIC (this is slower).
          pulseaudio Enable pulseaudio input support.
          rtmp Enable Real Time Messaging Protocol using librtmp instead the native implementation.
          ssl Enable SSL/TLS support using dev-libs/openssl or net-libs/gnutls.
          tools Build and install small tools like aviocat, cws2fws, graph2dot, ismindex, qt-faststart.
          twolame Enable MP2 encoding via media-sound/twolame as an alternative to the internal encoder
          vpx Enable vp8 encoding support using media-libs/libvpx.
          x265 Enable HEVC encoding with media-libs/x265.

          libva-utils

          drm Enables VA/DRM API support.

          makemkv

          gui Build the Qt5 GUI

          mjpegtools

          sdlgfx Enables y4mhist to display a graphical histogram

          mjpg-streamer

          input-control Plugin giving ability to control camera movement (only specific cameras)
          input-file Plugin that watches given directory and send it's content
          input-testpicture Plugin for sending compiled in, test pictures
          input-uvc Plugin that sends video stream from UVC compatible camera
          output-autofocus Auto focusing plugin
          output-file Plugin that saves received content under given location
          output-http Small HTTP server plugin which sends WWW directory content and streams image content
          output-rtsp Plugin which provides a mechanism to take snapshots with a trigger from a UDP packet
          output-udp Plugin receiving content over UDP and storing to a directory
          www Installs WWW content

          motion

          mmal Enables Multi-Media Abstraction Layer (MMAL) decoding support: Available e.g. on the Raspberry Pi.

          motiontrack

          multiprocess Enables multi-process support (SMP/cluster) for motiontrack programs

          mplayer

          bl Blinkenlights video output
          bluray Enable playback of Blu-ray filesystems
          bs2b Enable Bauer stereophonic-to-binaural headphone filter
          cdio Use libcdio for CD support (instead of cdparanoia)
          cdparanoia Enable cdparanoia (audio CD ripper) support
          cpudetection Enables runtime CPU detection (useful for binpkgs, compatibility on other CPUs)
          dvdnav Use forked libdvdnav, navigate menus in GUIs
          enca Enables support for charset discovery and conversion
          faac Use external faac library for AAC encoding
          faad Use external faad library for AAC decoding
          libmpeg2 Build support for mpeg2 over media-libs/libmpeg2 rather than using ffmpeg.
          live Enables live.com streaming media support
          md5sum Enables md5sum video output
          mng MNG input support
          network Enables network streaming support
          nut Enables support for the NUT container format
          osdmenu Enables support for on-screen display (OSD) menus
          pnm Add PNM video output option, to create PPM/PGM/PGMYUV images
          pvr Enable Video4Linux2 MPEG PVR
          radio Enable V4L2 radio interface and support
          rar Enable Unique RAR File Library
          rtc Enables usage of the linux real time clock. The alternative is software emulation of rtc
          rtmp Enables RTMPDump Streaming Media support
          shm Enable support for shm
          tga Enables Targa video output
          toolame Enable toolame MPEG-2 encoding
          tremor Enable internal support for Vorbis
          twolame Enable twolame MPEG-2 encoding
          vcd Enables VCD support
          vidix Support for vidix video output
          yuv4mpeg Enables yuv4mpeg video output
          zoran Enables ZR360[56]7/ZR36060 video output

          mpv

          archive Enable support for various archive formats via app-arch/libarchive
          bluray Enable playback of Blu-ray filesystems
          cli Build mpv CLI player
          cplugins Enable C plugins support
          cuda Enable hardware video decoding via Nvidia CUDA
          drm Enable Kernel Mode Setting / Direct Rendering Manager based video output
          egl Enable support for various EGL-based video outputs / backends
          gamepad Enable gamepad input support
          gbm Enable Graphics Buffer Manager based EGL video backend
          jpeg Enable support for saving screenshots in JPEG format
          libass Enable OSD (On Screen Display) and subtitles support via media-libs/libass
          libmpv Build mpv shared library
          lua Enable Lua scripting, OSC (On Screen Controller) GUI and net-misc/youtube-dl hook-script
          opengl Enable support for various OpenGL-based video backends
          raspberry-pi Enable support for the Raspberry Pi
          rubberband Enable high quality pitch correction via media-libs/rubberband
          sdl Enable media-libs/libsdl2 based video and audio outputs (Note: these outputs exist for compatibility reasons only, avoid if possible)
          tools Install extra tools: mpv_identify.sh, mpv_idet.sh, and umpv
          uchardet Enable subtitles charset discovery via app-i18n/uchardet
          vulkan Enable support for various Vulkan-based video backends
          zimg Enable libzimg support (for vf_fingerprint)

          noad

          libmpeg2 Build support for mpeg2 over media-libs/libmpeg2 rather than using ffmpeg

          nvidia_video_sdk

          tools Build and install example tools.

          obs-studio

          fdk Enable libfdk support for AAC encoding.
          imagemagick Use ImageMagick for image loading instead of FFmpeg.
          luajit Build support for scripting via Luajit.
          nvenc Enable NVENC encoding for nVidia video cards.
          python Build support for scripting via Python 3.
          speex Enable noise suppression filter support via media-libs/speexdsp.
          ssl Build support for TLS/SSL connections (RTMPS) via net-libs/mbedtls.
          vlc Build support for using media-video/vlc as a media source.

          ogmrip

          ogm Support for OGM container format
          srt Support for SRT subtitle format

          orion

          mpv Use the media-video/mpv player (upstream default)
          qtav Use the media-libs/qtav player
          qtmedia Use the dev-qt/qtmultimedia

          peek

          keybinder Enable support for global hotkeys using dev-libs/keybinder

          simplescreenrecorder

          asm Enable x86 assembly optimisation.
          vpx Enable VP8 codec support via media-libs/libvpx.

          smplayer

          autoshutdown Enable the option to shutdown your computer after finishing the playlist. This requires dev-qt/qtdbus as dependency.
          mpris Enable support for MPRIS2 (Media Player Remote Interfacing Specification, version 2), a DBus interface for remote control, which requires dev-qt/qtdbus as dependency.

          subtitlecomposer

          mpv Build mpv backend support

          syncplay

          client Install Syncplay client
          server Install Syncplay server
          vlc Enable VLC2.x support

          totem

          lirc Enable support for controlling Totem with a remote control using app-misc/lirc
          nautilus Enable the nautilus extension
          python Build dev-lang/python using plugins (dbusservice for notifications and MPRIS control, interactive python console and opensubtitles lookup)
          vala Build the rotation plugin, which allows videos to be rotated if they are in the wrong orientation

          transcode

          mjpeg Enables mjpegtools support
          nuv NuppelVideo container format demuxing
          pic disable optimized assembly code that is not PIC friendly
          postproc Build with ffmpeg libpostproc support

          vdr

          alternatechannel Use alternate channel on record
          bidi fribidi support, for languages, written from right to left
          graphtft support for vdr-graphtft plugin up from version 0.1.7
          html Install HTML documentation
          kbd enable keyboard support as remote device
          mainmenuhooks Allows to replace main menu entries by some special plugins (like epgsearch, extrecmenu, ...)
          menuorg Enables support for the media-plugins/vdr-menuorg
          menuselection adds support for menu hotkeys of double digits
          naludump Removes NALU fill data from h.264-Streams of TS files
          permashift permanent timeshift by recording live TV into RAM, need plugin media-plugins/vdr-permashift
          pinplugin Support for media-plugins/vdr-pin
          resumereset rreset resume of EOF
          ttxtsubs support for media-plugins/vdr-ttxtsubs

          vlc

          X Enable support for e.g. fullscreen mode via X and the X C-language binding. It does not build a graphical interface
          aom Enable experimental support for AV1 codec
          archive Enable support for libarchive stream extractor
          aribsub Enable support for decoding ARIB STD-B24 subtitles
          bluray Enable libbluray for Blu-ray disc support
          chromaprint Enable libchromaprint for Chromaprint based audio fingerprinter support
          chromecast Enable experimental support for Google Chromecast
          dav1d Enable support for media-libs/dav1d AV1 decoder
          dc1394 Enable IIDC cameras support
          directx Enable Win32 DirectX, D3D11va and DxVA2 support
          dvbpsi Enable support for Mpeg-TS files (.ts, .m2ts, .mts) via media-libs/libdvbpsi
          encode Enable streaming-output support and videolan manager to control multiple streams from within one instance
          faad Enable AAC audio decoding library support via media-libs/faad2
          fdk Enable the Fraunhofer AAC codec library
          fluidsynth Enable Fluidsynth MIDI software synthesis (with external sound fonts)
          gcrypt Enable cryptography support via libgcrypt
          gme Enable support for media-libs/game-music-emu for playing various video game music formats
          gstreamer Enable GStreamer based decoding support (currently supports only video decoding)
          kate Adds support for Ogg Kate subtitles via libkate
          kms Enable kernel mode setting video output plugin via x11-libs/libdrm
          libplacebo Enable support for GPU accelerated video rendering with media-libs/libplacebo
          libtar Uses libtar instead of the built-in tar reader for reading custom skins
          libtiger Enable Ogg Kate subtitles rendering using libtiger
          linsys Enable support for Linux Linear Systems Ltd. SDI and HD-SDI input cards
          live Enable live555 streaming media support (client support for rtsp)
          lua Enable Lua scripting support, needed for including support for Jamendo (online music platform) and similar things
          macosx-notifications Enable Mac OS X notifications module (formerly growl)
          matroska Enable matroska support using reference libraries (fallback on other existing matroska support if disabled, i.e., matroska enabled FFmpeg)
          mpeg Add libmpeg2 support for mpeg-1 and mpeg-2 video streams
          nfs Enable support for nfs protocol via net-fs/libnfs
          omxil Enable OpenMAX Integration Layer codec module
          opencv Enable OpenCV (computer vision) filter module
          optimisememory Enable optimisation for memory rather than performance
          postproc Enable image post-processing via libpostproc (part of FFmpeg)
          projectm Enable the projectM visualization plugin
          run-as-root Allows vlc to start for root. Don't enable this unless you have a very specific (e.g. embedded) need for it!
          sdl-image Enable sdl image video decoder (depends on sdl)
          sftp Enable libssh2 to support SFTP file transfer
          shout Enable libshout output
          sid Adds support for playing C64 SID files through media-libs/libsidplay:2
          skins Enable support for the skins2 interface
          soxr Enable SoX Resampler support via media-libs/soxr
          srt Enable support for Secure Reliable Transport (SRT) via net-libs/srt
          tremor Enable tremor, a fixed-point version of the Ogg Vorbis decoder
          twolame Enable twolame support (MPEG Audio Layer 2 encoder)
          upnp Enable support for the Intel SDK stack based UPnP discovery module instead of CyberLink
          vpx Enable the decoder(s) from the WebM VP8 / VP9 Codec SDK
          x265 Support X265 Encoder
          zeroconf Enable support for zero-configuration networking via avahi
          zvbi Enable support for teletext subtitles via the zvbi library

          webcamoid

          headers Install development headers
          libuvc Build with libuvc support
          qtaudio Enable audio capture/play via dev-qt/qtmultimedia
          v4lutils 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          videoeffects Build video effects

          x264-encoder

          avs enable AvxSynth support in the AviSynth input module
          ffmpegsource Enable ffmpegsource aka ffms support, disables lavf
          interlaced Enable interlaced encoding support, this can decrease encoding speed by up to 2%

          xine-ui

          vdr Enables Video Disk Recorder support

          yle-dl

          php Use a PHP script as download backend
          youtube-dl Use youtube-dl script as a download backend

          net-analyzer

          2ping

          server Install the server init scripts.

          argus

          libtirpc Build against net-libs/libtirpc for RPC support

          argus-clients

          ft Enable support for flow packets through net-analyzer/flow-tools

          barnyard

          sguil Enable sguil (The Analyst Console for Network Security Monitoring) support

          barnyard2

          gre Enable GRE support
          mpls Enable support for mpls networks
          sguil Enable sguil (The Analyst Console for Network Security Monitoring) support

          bwm-ng

          csv Enable csv output
          html Enable html output

          cacti

          doc install html documentation

          check_mk_agent

          apache_status 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          inventory Install check_mk-agent linux inventory plugin.
          logwatch Install check_mk-agent logwatch plugin.
          mysql Install check_mk-agent mysql plugin.
          nfsexports Install check_mk-agent nfsexports plugin.
          postgres Install check_mk-agent postgres plugin.
          smart Install check_mk-agent S.M.A.R.T plugin.
          zypper Install check_mk-agent zypper plugin.

          echoping

          http enable support for http protocol.
          icp enable support for ICP (used to monitor proxies).
          priority enable socket priority support.
          smtp enable support for SMTP protocol.
          tos enable support for TOS (TYpe Of Service).

          ettercap

          plugins Install ettercap plugins (et_*.so)

          flent

          plots Enable drawing plots

          flowgrind

          pcap Enable packet capturing support using net-libs/libpcap

          fprobe

          messages enable console messages

          goaccess

          btree Enable Tokyo Cabinet's on-disk B+ Tree database backend
          geoipv2 Enable support for GeoIP2 through dev-libs/libmaxminddb
          getline Use GNU getline() to parse full line requests
          tokyocabinet Enable Tokyo Cabinet's on-memory hash database backend

          gr-fosphor

          glfw enable GLFW based interface

          graphite-web

          carbon Enable carbon support
          memcached Enable memcached support

          greenbone-security-assistant

          extras Pdf results, extra fonts, html docs support

          gvm

          cli Command Line Interface for OpenVAS Scanner
          cron A cron job to update GVM's vulnerability feeds daily
          extras Extra fonts, pdf-results! and html docs support
          gsa Greenbone Security Assistant (WebUI)
          ospd Enable support for scanner wrappers

          gvm-libs

          extras Html docs support

          gvmd

          extras Html docs support

          hexinject

          experimental Install experimental packets.tcl
          tools Install hex2raw and prettypacket tools

          httping

          tfo Enable support for TCP Fast Open

          hydra

          gcrypt Enable radmin2 support through dev-libs/libgcrypt
          libssh Enable SSH support through net-libs/libssh
          mongodb MongoDB support through dev-libs/mongo-c-driver
          ncp NCP protocol (NetWare) support through net-fs/ncpfs

          icinga

          contrib additional scripts
          eventhandler Adds support for running custom scripts whenever a host or service state change occurs
          idoutils Adds DB support
          lighttpd Adds Lighttpd support
          plugins Adds support for nagios plugins
          web Adds generic web interface support

          icinga-web

          pnp Enables pnp4nagios integration

          icinga2

          classicui Adds support for the old interface
          console Adds support for line-editing in the console
          lto Adds support for link time optimization
          mail Allows for mailing of alerts
          mariadb Enable support for the mariadb database backend
          nano-syntax Adds support for syntax used in the nano editor
          plugins Adds support for nagios plugins

          ipsumdump

          nanotimestamp Enable timestamps with nano-second resolution

          linkchecker

          sqlite Mozilla Bookmark parsing

          metasploit

          development Install dependencies needed for metasploit and exploit development
          nexpose Enable the plugin to integrate with nexpose
          oracle Enable restricted oracle modules which have additional deps
          pcap Enable libpcap for packet sniffing

          mk-livestatus

          nagios4 Generate a net-analyzer/nagios-4 compatible plugin

          monitoring-plugins

          dns Install net-dns/bind-tools required for monitoring DNS servers. Disabling the flag does not remove any plugins.
          fping Install net-analyzer/fping required for fancy ping monitoring. Disabling the flag does not remove any plugins.
          game Install games-util/qstat required for monitoring FPS servers. Disabling the flag does not remove any plugins.
          snmp Install dev-perl/Net-SNMP and net-analyzer/net-snmp required for monitoring SNMP values. Disabling the flag does not remove any plugins.
          ssh Install net-misc/openssh required for monitoring SSH servers. Disabling the flag does not remove any plugins.

          munin

          asterisk Install the packages required for monitoring Asterisk. Disabling the flag does not remove any plugin files.
          cgi Install the CGI-compatible scripts for on-the-fly generation of web pages and graphs. This is only meaningful if the minimal USE flag is disabled.
          dhcpd 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          doc Build and install a local copy of the HTML documentation for the whole software. This requires dev-python/sphinx to process the documentation sources.
          http Install dev-perl/libwww-perl required for monitoring HTTP-based services such as Apache and nginx. Disabling the flag does not remove any plugin file.
          ipmi Install sys-apps/ipmitool required for monitoring IPMI sensors. Disabling the flag does not remove any plugin file.
          ipv6 Add support for IPv6 in munin-node. IPv6 support for the master is always enabled, but the node requires a newer version of dev-perl/Net-Server, capable of listening to IPv6 sockets.
          irc Install the packages required for monitoring IRC. Disabling the flag does not remove any plugin files.
          java Build the Java-based plugins to monitor JMX-compatible applications. Disabling the flag removes the jmx monitoring plugins.
          memcached Install the packages required for memcached monitoring. Disabling the flag does not remove any plugin files.
          minimal Only install munin-node and its plugins. This excludes the scripts to generate the web pages and the graphs.
          mysql Install the packages required for monitoring MySQL. Disabling the flag does not remove any plugin files.
          postgres Install the packages required for monitoring PostgreSQL. Disabling the flag does not remove any plugin files.
          syslog Configure the node by default to log on syslog. This requires the presence of virtual/perl-Sys-Syslog. As of version 2.0.2, the master scripts only log to file, and not to syslog.

          nagios-core

          classicui use the classic web theme
          lighttpd install www-servers/lighttpd config
          web enable web interface

          nagios-plugin-check_raid

          3ware Support 3ware RAID controllers
          aacraid Support Adaptec AAC-RAID controllers
          dmraid Support Device-Mapper RAID
          hpa Support HP Array controllers
          hpsa Support HP SmartArray (CCISS) controllers
          megaraid-sas Support LSI MegaRAID SAS controllers
          megaraid-scsi Support LSI MegaRAID SCSI controllers
          mpt Support LSI MPT Fusion controllers
          mpt-sas2 Support LSI SAS-2 controllers

          nagios-plugins

          nagios-dns Install net-dns/bind-tools required for monitoring DNS servers. Disabling the flag does not remove any plugin file.
          nagios-game Install games-util/qstat required for monitoring FPS servers. Disabling the flag does not remove any plugin file.
          nagios-ping Install net-analyzer/fping required for fancy ping monitoring. Disabling the flag does not remove any plugin file.
          snmp Install dev-perl/Net-SNMP required for monitoring SNMP values. Disabling the flag does not remove any plugin file.
          ssh Install net-misc/openssh required for monitoring SSH servers. Disabling the flag does not remove any plugin file.

          nagios-plugins-flameeyes

          smart Install sys-apps/smartmontools required for S.M.A.R.T. disk monitoring. Disabling the flag removes the plugin file. This plugin also requires the sudo flag to be enable.

          nagios-plugins-linux-madrisan

          curl Build check_docker which requires net-misc/curl

          net-snmp

          elf Enable the use of elf utils to check uptime on some systems
          kmem Enable usage of /dev/kmem
          mfd-rewrites Use MFD rewrites of mib modules where available
          netlink Use dev-libs/libnl to fetch TCP statistics instead of using /proc/net/tcp (Linux only).
          pcap Install snmppcap which reads from PCAP files and writes to the SNMP transport
          pci Use libpci (from sys-apps/pciutils) to look up network interface description. This feature is only available on Linux.
          rpm Enable monitoring of app-arch/rpm. This flag requires the bzip2 and zlib flags to be enabled as well.
          smux Enable support for the legacy smux protocol (superseded by agentx)
          ucd-compat Build UCD compatibility library. Increases significantly the install size.

          netdata

          compression Enable compression via zlib
          dbengine Enable the Netdata database engine
          ipmi Install sys-apps/ipmitool required for monitoring IPMI sensors.
          nfacct Enable the nfacct plugin
          nodejs Enable use of nodejs (which some plugins use)
          tor Enable monitoring of tor
          xen Enable monitoring of xen

          netperf

          demo Emit interim results during the run. May affect results

          nfdump

          compat15 Enable read support for nfdump data files created with nfdump 1.5.x
          ftconv Build the flow-tools to nfdump converter
          nfprofile Build nfprofile used by NfSen
          nftrack Build nfprofile used by PortTracker
          readpcap Build nfcapd collector to read from pcap file instead ofnetwork data
          sflow Build sflow collector sfcpad

          nmap

          libssh2 Enable SSH support through net-libs/libssh2
          ncat Install the ncat utility
          ndiff Install the ndiff utility
          nmap-update Install nmap-update, which uses dev-vcs/subversion to update nmap scripts in your home directory
          nping Install the nping utility
          nse Include support for the Nmap Scripting Engine (NSE)
          system-lua Use dev-lang/lua instead of the bundled liblua
          zenmap Install the GTK+ based nmap GUI, zenmap

          nrpe

          command-args Build support for specifying the command-line arguments from the Nagios/Icinga master. Make sure you understand the implications of this flag as it can be a security risk.

          nsca

          crypt Build support for crypted communication with nsca, through dev-libs/libmcrypt. It's recommended not to disable this flag unless all the communication will be handled in an absolutely safe environment.
          minimal Only build and install the send_nsca command and not the daemon. This allows a very minimal install with no overhead when setting up a node.

          openvas-libraries

          extras Html docs support
          ldap Enable support for ldap
          radius Enable support for radius

          openvas-manager

          extras Html docs support

          openvas-scanner

          cron Install a cron job to update GVM's feed daily.
          extras Html docs support

          ospd

          extras Html docs support

          ossec-hids

          agent Build "agent" installation target (see package description)
          hybrid Build "hybrid" installation target
          local Build "local" installation target
          server Build "server" installation target

          pchar

          pcap Use the net-libs/libpcap library

          pinger

          gtk2 Install the gtkpinger GUI utility based on x11-libs/gtk+:2
          gtk3 Install the gtkpinger GUI utility based on x11-libs/gtk+:3

          pmacct

          64bit Use 64bit counters instead of 32bit ones
          bgp-bins Link BGP daemon binaries
          bmp-bins Link BMP daemon binaries
          geoipv2 Enable support for GeoIP2 through dev-libs/libmaxminddb
          jansson Enable support for JSON through dev-libs/jansson
          kafka Enable support for Apache Kafka through dev-libs/librdkafka
          l2 Enable Layer-2 features and support
          mongodb Enable support for MongoDB through dev-libs/mongo-c-driver
          ndpi Enable support for nDPI through net-libs/nDPI
          nflog Enable support for NFLOG through uacctd
          plabel Enable IP prefix labels
          rabbitmq Enable support for RabbitMQ through net-libs/rabbitmq-c
          st-bins Link Streaming Telemetry daemon binaries
          traffic-bins Link IPv4/IPv6 traffic accounting binaries
          zmq Enable support for ZeroMQ through net-libs/zeromq

          pnp4nagios

          icinga Build against net-analyzer/icinga2 or net-analyzer/icinga instead of net-analyzer/nagios-core
          nagios Build against net-analyzer/nagios-core (the default)

          prelude-lml

          tls Enables Prelude LML support Syslog through TLS using net-libs/gnutls.

          rrdcollect

          exec Enable exec:/// support
          librrd Use the librrd library from net-analyzer/rrdtool

          rrdtool

          graph Enable support for graphing functions
          rados Enable support for librados from sys-cluster/ceph
          rrdcgi Build rrdcgi support

          sancp

          sguil Enable sguil (The Analyst Console for Network Security Monitoring) support

          sarg

          gd Enable support for graphs in reports through media-libs/gd
          pcre Enable support for regular expressions in the hostalias file through dev-libs/libpcre

          scanlogd

          nids Use net-libs/libnids for packet capturing
          pcap Use net-libs/libpcap for packet capturing

          scapy

          pyx Enable dev-python/pyx support for psdump/pdfdump commands
          tcpreplay 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          smokeping

          dig Install net-dns/bind-tools for dig functionality
          echoping Install net-analyzer/echoping for echoping functionality
          ssh Install ssh functionality
          telnet Install dev-perl/Net-Telnet for telnet functionality

          sngrep

          eep Enable EEP packet send/receive support
          gnutls Use net-libs/gnutls to parse captured TLS packets
          openssl Use dev-libs/openssl to parse captured TLS packets

          snort

          active-response Enables support for automatically sending TCP resets and ICMP unreachable messages to terminate connections. Used with inline deployments.
          control-socket Enables Snort's control socket.
          file-inspect Enables extended file inspection capabilities.
          flexresp3 Enables support for new flexable response preprocessor for enabling connection tearing for inline deployments. Replaces flexresp and flexresp2.
          gre Enable support for inspecting and processing Generic Routing Encapsulation (GRE) packet headders. Only needed if you are monitoring GRE tunnels.
          high-availability Enables high-availability state sharing.
          inline-init-failopen Enables support to allow traffic to pass (fail-open) through inline deployments while snort is starting and not ready to begin inspecting traffic. If this option is not enabled, network traffic will not pass (fail-closed) until snort has fully started and is ready to perform packet inspection.
          large-pcap-64bit Allows Snort to read pcap files that are larger than 2 GB. ONLY VALID FOR 64bit SYSTEMS!
          libtirpc Build against net-libs/libtirpc for RPC support
          linux-smp-stats Enable accurate statistics reporting through /proc on systems with multipule processors.
          non-ether-decoders Enable decoding of non-ethernet protocols such as TokenRing, FDDI, IPX, etc.
          open-appid Enable OpenAppID, an open, application-focused detection language and processing module for Snort that enables users to create, share, and implement application detection. Requires dev-lang/luajit.
          perfprofiling Enables support for preprocessor and rule performance profiling using the perfmonitor preprocessor.
          ppm Enables support for setting per rule or per packet latency limits. Helps protect against introducing network latency with inline deployments.
          react Enables support for the react rule keyword. Supports interception, termination, and redirection of HTTP connections.
          reload-error-restart Enables support for completely restarting snort if an error is detected durring a reload.
          shared-rep 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          side-channel Enables Snort's the side channel.
          sourcefire Enables Sourcefire specific build options, which include --enable-perfprofiling and --enable-ppm.

          suricata

          af-packet Enable AF_PACKET support
          control-socket Enable unix socket
          cuda Enable NVIDIA Cuda computations support
          detection Enable detection modules
          logrotate Install logrotate rule
          nflog Enable libnetfilter_log support
          nfqueue Enable NFQUEUE support for inline IDP
          redis Enable Redis support
          rules Install default ruleset

          symon

          perl Enables a generic perl symux client
          symon Enables the system monitor. Offers no functionality but monitoring and forwarding of measured data
          symux Enables the multiplexer which stores incoming symon streams on disk in RRD (net-analyzer/rrdtool) files

          tcpdump

          drop-root Drop privileges to tcpdump:tcpdump when run as root
          smi Build with net-libs/libsmi to load MIBs on the fly to decode SNMP packets

          tcpreplay

          pcapnav Enable if you want the jump to byte offset feature via net-libs/libpcapnav
          tcpdump Use net-analyzer/tcpdump for packet decoding feature

          testssl

          bundled-openssl Install precompiled versions of OpenSSL for greater testing coverage

          wapiti

          kerberos Support Kerberos authentication
          ntlm Support NTLM authentication

          wireshark

          adns Use net-dns/c-ares to resolve DNS names
          androiddump Install androiddump, an extcap interface to capture from Android devices
          bcg729 Use media-libs/bcg729 for G.729 codec support in RTP Player
          brotli Use app-arch/brotli for compression/decompression
          capinfos Install capinfos, to print information about capture files
          captype Install captype, to print the file types of capture files
          ciscodump Install ciscodump, extcap interface to capture from a remote Cisco router
          dftest Install dftest, to display filter byte-code, for debugging dfilter routines
          dpauxmon Install dpauxmon, an external capture interface (extcap) that captures DisplayPort AUX channel data from linux kernel drivers
          dumpcap Install dumpcap, to dump network traffic from inside wireshark
          editcap Install editcap, to edit and/or translate the format of capture files
          http2 Use net-libs/nghttp2 for HTTP/2 support
          libxml2 Use dev-libs/libxml2 for handling XML configuration in dissectors
          maxminddb Use dev-libs/libmaxminddb for IP address geolocation
          mergecap Install mergecap, to merge two or more capture files into one
          minizip Build with zip file compression support
          netlink Use dev-libs/libnl
          pcap Use net-libs/libpcap for network packet capturing (build dumpcap, rawshark)
          plugin-ifdemo Install plugin interface demo
          plugins Install plugins
          randpkt Install randpkt, a utility for creating pcap trace files full of random packets
          randpktdump Install randpktdump, an extcap interface to provide access to the random packet generator (randpkt)
          reordercap Install reordercap, to reorder input file by timestamp into output file
          sbc Use media-libs/sbc for playing back SBC encoded packets
          sdjournal Install sdjournal, an extcap that captures systemd journal entries
          sharkd Install sharkd, the daemon variant of wireshark
          smi Use net-libs/libsmi to resolve numeric OIDs into human readable format
          spandsp Use media-libs/spandsp for for G.722 and G.726 codec support in the RTP Player
          sshdump Install sshdump, an extcap interface to capture from a remote host through SSH
          text2pcap Install text2pcap, to generate a capture file from an ASCII hexdump of packets
          tfshark Install tfshark, a terminal-based version of the FileShark capability
          tshark Install tshark, to dump and analyzer network traffic from the command line
          udpdump Install udpdump, to get packets exported from a source (like a network device or a GSMTAP producer) that are dumped to a pcap file

          zabbix

          agent Enable zabbix agent (for to-be-monitored machines)
          frontend Enable zabbix web frontend
          ipv6 Turn on support of IPv6
          java Enable Zabbix Java JMX Management Gateway
          libxml2 Use libxml2 client library
          odbc Enable Database Monitor and use UnixODBC Library by default
          openipmi Enable openipmi things
          proxy Enable proxy support
          server Enable zabbix server
          ssh SSH v2 based checks
          static Build statically linked binaries

          zmap

          json Add support to store results JSON based
          mongo Add support for storing in a mongo DB via dev-db/mongodb
          redis Add support for storing in a redis DB via dev-libs/hiredis

          net-dialup

          accel-ppp

          ipoe Build IPoE kernel module
          shaper Support for traffic shaping
          valgrind Compile in valgrind hints

          freeradius

          memcached Include dev-libs/libmemcached in caching drivers
          pcap Build the RADIUS sniffer which requires net-libs/libpcap.
          redis Include support for Redis database
          rest Include support for sending and receiving HTTP requests

          freeradius-client

          scp Add service type hints derived from username prefix
          shadow Enable shadow password support

          mgetty

          fax Enables fax support
          fidonet Enables FidoNet support

          openl2tp

          client Enable l2tp client.
          dmalloc Enable debugging using dev-libs/dmalloc.
          rpc Enable RPC control management. This flag is required for l2tpconfig to be built and used.
          server Enable l2tp server.
          stats Enable status files. Note: when they are used, this hampers performance of the daemon.

          ppp

          activefilter Enables active filter support
          atm Enables ATM (Asynchronous Transfer Mode) protocol support
          dhcp Installs PPP DHCP client plugin for IP address allocation by a DHCP server (see //www.netservers.co.uk/gpl/)
          eap-tls Enables support for Extensible Authentication Protocol and Transport Level Security (see //www.nikhef.nl/~janjust/ppp/index.html)
          gtk Installs GTK+ password prompting program that can be used by passprompt.so PPP plugin for reading the password from a X11 input terminal
          ipv6 Enables support for IP version 6
          pam Enables PAM (Pluggable Authentication Modules) support
          radius Enables RADIUS support

          xl2tpd

          dnsretry Patch for host lookup retries, activated by redial feature
          kernel Enable kernel interface for PPPoL2TP

          net-dns

          avahi

          autoipd Build and install the IPv4LL (RFC3927) network address configuration daemon
          bookmarks Install the avahi-bookmarks application (requires dev-python/twisted-core and dev-python/twisted-web)
          gtk3 Build the avahi-ui-gtk3 library, and use gtk3 for the avahi utilities under USE=utils
          howl-compat Enable compat libraries for howl
          mdnsresponder-compat Enable compat libraries for mDNSResponder

          bind

          dlz Enables dynamic loaded zones, 3rd party extension
          dnsrps Enable the DNS Response Policy Service (DNSRPS) API, a mechanism to allow an external response policy provider
          dnstap Enables dnstap packet logging
          fixed-rrset Enables fixed rrset-order option
          geoip2 500 Internal Server Error

          Internal Server Error

          The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

          gssapi Enable gssapi support
          json Enable JSON statistics channel
          lmdb Enable LMDB support to store configuration for 'addzone' zones
          urandom Use /dev/urandom instead of /dev/random

          bind-tools

          gssapi Enable gssapi support

          ddclient

          examples Install various example files, like for cron.
          iproute2 Use sys-apps/iproute2 instead of sys-apps/net-tools for interaction.

          dnsdist

          dnscrypt Enable the ability to act as a DNSCrypt server
          fstrm Enable support for fstrm via dev-libs/fstrm
          regex Enable support for regular expression matching via dev-libs/re2
          remote-logging Enable support for remote logging via dev-libs/protobuf
          ssl Enable support for and encrypted client-server communication via dev-libs/libsodium

          dnsmasq

          auth-dns