# Copyright 1999-2024 Gentoo Authors # Distributed under the terms of the GNU General Public License v2 # Keep them sorted 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) 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 asm - Enable using assembly for optimization atm - Enable Asynchronous Transfer Mode protocol support apparmor - Enable support for the AppArmor application security system appindicator - Build in support for notifications using the libindicate or libappindicator plugin audiofile - Add support for libaudiofile where applicable audit - Enable support for Linux audit subsystem using sys-process/audit avif - Add AV1 Image Format (AVIF) support 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 Gentoo specific branding brotli - Enable Brotli compression support build - !!internal use only!! DO NOT SET THIS FLAG YOURSELF!, used for creating build images and the first half of bootstrapping [make stage1] bzip2 - Enable bzip2 compression support cairo - Enable support for the cairo graphics library calendar - Add support for calendars (not using mcal!) caps - Use Linux capabilities library to control privilege cdb - Add support for the CDB database engine from the author of qmail 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 cuda - Enable NVIDIA CUDA support (computation on GPU) 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 https://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 dist-kernel - Enable subslot rebuilds on Distribution Kernel upgrades 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) egl - Enable EGL (Embedded-System Graphics Library, interfacing between windowing system and OpenGL/GLES) support 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 - Add support for FreeWnn kana to kanji conversion engine 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 gles2 - Enable GLES 2.0 (OpenGL for Embedded Systems) support (independently of full OpenGL, see also: gles2-only) gles2-only - Use GLES 2.0 (OpenGL for Embedded Systems) or later instead of full OpenGL (see also: gles2) 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 gui - Enable support for a graphical user interface 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. heif - Enable support for ISO/IEC 23008-12:2017 HEIF/HEIC image format hscolour - Include coloured haskell sources to generated documentation (dev-haskell/hscolour) http2 - Enable support for the HTTP/2 protocol 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 jack - 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 Gentoo 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 jpegxl - Add JPEG XL image support kde - Add support for software made by KDE, a free software community kerberos - Add kerberos support keyring - Enable support for freedesktop.org Secret Service API password store ladspa - Enable the ability to support ladspa plugins lame - Prefer using LAME libraries for MP3 encoding support 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 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 - Enable desktop notification support 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 llvm-libunwind - Use sys-libs/llvm-libunwind instead of sys-libs/libunwind lm-sensors - Add linux lm-sensors (hardware sensors) support lto - Enable Link-Time Optimization (LTO) to optimize the build lua - Enable Lua scripting support lz4 - Enable support for lz4 compression (as implemented in app-arch/lz4) lzip - Enable support for lzip compression lzma - Support for LZMA compression algorithm lzo - Enable support for lzo compression m17n-lib - Enable m17n-lib support 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 man - Build and install man pages 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 - Install a very minimal build (disables, for example, plugins, fonts, most drivers, non-critical features) 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 modules-compress - Install compressed kernel modules (if kernel config enables module compression) modules-sign - Cryptographically sign installed kernel modules (requires CONFIG_MODULE_SIG=y in the kernel) 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 native-extensions - Build native (e.g. C, Rust) extensions in addition to pure (e.g. Python) code (usually speedups) ncurses - Add ncurses support (console display library) neXt - Enable neXt toolkit netcdf - Enable NetCDF data format support networkmanager - Enable net-misc/networkmanager support nis - Support for NIS/YP services nls - Add Native Language Support (using gettext - GNU locale utilities) 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) nvenc - Add support for NVIDIA Encoder/Decoder (NVENC/NVDEC) API for hardware accelerated encoding and decoding on NVIDIA cards (requires x11-drivers/nvidia-drivers) 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 - Enable support for importing (and exporting) OFX (Open Financial eXchange) data files ogg - Add support for the Ogg container format (commonly used by Vorbis, Theora and flac) openal - Add support for the Open Audio Library opencl - Enable OpenCL support (computation on GPU) 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" opentype-compat - Convert BDF and PCF bitmap fonts to OTB wrapper format 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 - Add support for OSS (Open Sound System) otf - Install OpenType font versions 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 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 - Build optional KDE plasma addons plotutils - Add support for plotutils (library for 2-D vector graphics) png - Add support for libpng (PNG images) policykit - Enable PolicyKit (polkit) 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 Gentoo Prefix offset installation is used profile - Add support for software performance analysis (will likely vary from ebuild to ebuild) pulseaudio - Add sound server support via media-libs/libpulse (may be PulseAudio or PipeWire) 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 qt6 - Add support for the Qt 6 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) screencast - Enable support for remote desktop and screen cast using PipeWire 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 secureboot - Automatically sign efi executables using user specified key 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 sid - Enable SID (Commodore 64 audio) file 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) 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) speech - Enable text-to-speech support 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 strip - Allow symbol stripping to be performed by the ebuild for special files subversion - Enable subversion (version control system) support suid - Enable setuid root program(s) 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 telemetry - Send anonymized usage information to upstream so they can better understand our users test - Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently) test-rust - Enable important test dependencies that require Rust toolchain 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 ttf - Install TrueType font versions udev - Enable virtual/udev integration (device discovery, power and storage device support, etc) udisks - Enable storage management support (automounting, volume monitoring, etc) uefi - Enable support for the Unified Extensible Firmware Interface 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 valgrind - Enable annotations for accuracy. May slow down runtime slightly. Safe to use even if not currently using dev-debug/valgrind 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 verify-sig - Verify upstream signatures on distfiles 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 vulkan - Add support for 3D graphics and computing via the Vulkan cross-platform API 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 compression zsh-completion - Enable zsh completion support zstd - Enable support for ZSTD compression