Graphics library that outputs text instead of pixels

http://caca.zoy.org/

Library to support cross-platform AES encryption

https://github.com/libyal/libcaes

Implementation of the Freedesktop sound theme spec

https://0pointer.de/lennart/projects/libcanberra/

Implementation of the Freedesktop sound theme spec

https://0pointer.de/lennart/projects/libcanberra/

Implementation of the Freedesktop sound theme spec

https://0pointer.de/lennart/projects/libcanberra/

CBOR protocol implementation for C and others

https://github.com/PJK/libcbor

Generic driver for USB CCID and ICCD

https://ccid.apdu.fr/

Library for playing audio CDs

http://libcdaudio.sourceforge.net/

Library to access data on a CDDB server

http://libcddb.sourceforge.net/

Compact Disc Input and Control Library

http://www.gnu.org/software/libcdio/

Read audio from the CDROM directly as data

http://www.gnu.org/software/libcdio/

Library and tools for parsing Corel Draw file format

https://wiki.documentfoundation.org/DLP/Libraries/libcdr

C library aimed to provide a Gtk+ widget to display rasterized maps and markers

http://projects.gnome.org/libchamplain/

Tool to check shared library links

http://svn.idaemons.org/cgi-bin/viewvc.cgi/trunk/?root=libchk

Ultralightweight JSON parser in ANSI C

https://github.com/DaveGamble/cJSON

Required library functions for OpenCL C programming language

http://libclc.llvm.org/

Alternative configuration system for Compiz

Simple library for manipulating structured configuration files

https://www.hyperrealm.com/libconfig/libconfig.html

Configuration file parsing library

http://savannah.nongnu.org/projects/confuse/

Library for accessing the MusicBrainz cover art archive

https://coverartarchive.org/

CSS2 parsing library

http://www.freespiders.org/projects/libcroco/

GNOME application for managing encryption keys (PGP, SSH)

https://gitlab.gnome.org/GNOME/libcryptui

Cascading Style Sheets library

https://www.netsurf-browser.org/projects/libcss/

CUE Sheet Parser Library

https://github.com/lipnitsk/libcue

Lightweight C library that eases the writing of UNIX daemons

http://0pointer.de/lennart/projects/libdaemon/

WebRTC Data Channels, WebRTC Media Transport, and WebSockets library

https://github.com/paullouisageneau/libdatachannel

Double-array trie implementation library

https://linux.thai.net/projects/datrie/

Companion library to GObject and GTK

https://gitlab.gnome.org/GNOME/libdazzle

GLib and Gtk Implementation of the DBusMenu protocol

https://launchpad.net/libdbusmenu

Qt5 implementation of the DBusMenu protocol

https://launchpad.net/libdbusmenu-qt

1394-based DC Control Library

https://damien.douxchamps.net/ieee1394/libdc1394/

Free DTS Coherent Acoustics decoder

https://www.videolan.org/developers/libdca.html

Open source h.265 video codec

https://www.libde265.org

Client-side decorations library for Wayland client

https://gitlab.freedesktop.org/libdecor/libdecor

Fast, whole-buffer DEFLATE-based compression library

https://github.com/ebiggers/libdeflate

Generic Device Query and Monitor interface

https://github.com/freebsd/libdevq

Library to generate arbitrary sequence diffs

https://github.com/kristapsdz/libdiff

Library for creating MusicBrainz DiscIDs

http://musicbrainz.org/doc/libdiscid

EDID and DisplayID library

https://gitlab.freedesktop.org/emersion/libdisplay-info

Library for reading and writing Data Matrix barcodes

http://libdmtx.sourceforge.net/

Simple interface to low level networking routines

https://github.com/5u623l20/libdnet/

Standard library for Window Maker dock apps

http://solfertje.student.utwente.nl/~dalroi/libdockapp/

Document Object Model library

http://www.netsurf-browser.org/projects/libdom/

Userspace interface to kernel Direct Rendering Module services

https://dri.freedesktop.org/

Alsa compatibility library to build DSSI

http://www.smbolton.com/linux.html

Quasar DV codec (libdv): software codec for DV video encoding format

http://libdv.sourceforge.net/

Library for MPEG TS and DVB PSI tables decoding and generation

http://www.videolan.org/developers/libdvbpsi.html

Portable abstraction library for DVD decryption

https://www.videolan.org/developers/libdvdcss.html

Videolan version of the libdvdnav project

https://www.videolan.org/developers/libdvdnav.html

MPlayer version of the libdvdread project

https://www.videolan.org/developers/libdvdnav.html