global USE flags

cdinstall

Copy files from the CD rather than asking the user to copy them, mostly used with games

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

gsm

Add support for the gsm lossy speech compression codec

headers-only

Install only C headers instead of whole package. Mainly used by sys-devel/crossdev for toolchain bootstrap.

magic

Add support for file type detection via magic bytes (usually via libmagic from sys-apps/file)

mikmod

Add libmikmod support to allow playing of SoundTracker-style music files

python

Add optional support/bindings for the Python language

minimal

Install a very minimal build (disables, for example, plugins, fonts, most drivers, non-critical features)

savedconfig

Use this to restore your config from /etc/portage/savedconfig ${CATEGORY}/${PN}. Make sure your USE flags allow for appropriate dependencies

test

Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently)

accessibility

Add support for accessibility (eg 'at-spi' library)

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)

gtk-doc

Build and install gtk-doc based developer documentation for dev-util/devhelp, IDE and offline use

ayatana

Build in support for Ayatana notification using the libindicate or libappindicator plugin

build

!!internal use only!! DO NOT SET THIS FLAG YOURSELF!, used for creating build images and the first half of bootstrapping [make stage1]

multilib

On 64bit systems, if you want to be able to compile 32bit and 64bit binaries

ocamlopt

Enable ocamlopt support (ocaml native code compiler) -- Produces faster programs (Warning: you have to disable/enable it at a global scale)

seccomp

Enable seccomp (secure computing mode) to perform system call filtering at runtime to increase security of programs

verify-sig

Verify upstream signatures on distfiles

cdda

Add Compact Disk Digital Audio (Standard Audio CD) support

graphviz

Add support for the Graphviz library

gsl

Use the GNU scientific library for calculations

cddb

Access cddb servers to retrieve and submit information about compact disks

X

Add support for X11

Xaw3d

Add support for the 3d athena widget set

3dfx

Enable support for Voodoo chipsets, also called as 3DFX and TDFX

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)

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

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

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

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

Add support for the CDB database engine from the author of qmail

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)

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

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-only

Use GLES 2.0 or later instead of full OpenGL

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)

cdr

Add support for CD writer hardware

gtk

Add support for x11-libs/gtk+ (The GIMP Toolkit)

gstreamer

Add support for media-libs/gstreamer (Streaming media)

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

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

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

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

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

libav

Prefer libav over ffmpeg whenever both are supported

libnotify

Enable desktop notification support

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

Enable m17n-lib support

mad

Add support for mad (high-quality mp3 decoder library and cli frontend)

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

milter

Add sendmail mail filter (milter) support

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

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

Enable neXt toolkit

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

Add Native Language Support (using gettextGNU 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)

ocaml

Add support/bindings for the Ocaml language

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

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

Add support for OSS (Open Sound System)

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

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 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 support for PulseAudio sound server

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

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)

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 sqliteembedded 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

telemetry

Send anonymized usage information to upstream so they can better understand our users

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

qdbm

Add support for the qdbm (Quick Database Manager) library

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

vorbis

Add support for the OggVorbis audio codec

wavpack

Add support for wavpack audio compression tools

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)

vcd

Video CD support

wayland

Enable dev-libs/wayland backend

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

webkit

Add support for the WebKit HTML rendering/layout engine

webp

Add support for the WebP image format

wifi

Enable wireless network functions

vnc

Enable VNC (remote desktop viewer) support

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)

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

xcb

Support the X C-language Binding, a replacement for Xlib