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/

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

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/

CSS2 parsing library

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

GNOME application for managing encryption keys (PGP, SSH)

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

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/

Double-array trie implementation library

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

Companion library to GObject and GTK

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

Free DTS Coherent Acoustics decoder

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

Generic Device Query and Monitor interface

https://github.com/freebsd/libdevq

Library for creating MusicBrainz DiscIDs

http://musicbrainz.org/doc/libdiscid

Reference DLNA open-source implementation

https://libdlna.geexbox.org/

Library for reading and writing Data Matrix barcodes

http://libdmtx.sourceforge.net/

DMX extension library

http://www.freedesktop.org/Software/xorg

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/

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/

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

Collection of C++/Qt classes designed to use the APIs of The Echo Nest

https://github.com/lfranchi/libechonest

Command line editor library

http://thrysoee.dk/editline/

Public ELF file access library similar to libelf(3) in Solaris

https://web.archive.org/web/20181111033959/www.mr511.de/software/english.html

Enhanced Metafile Library

http://libemf.sourceforge.net/

Small epoll implementation using kqueue

https://github.com/jiixyj/epoll-shim

Library to handle OpenGL function pointer management

https://github.com/anholt/libepoxy

Library for generating documents in ePub format

http://libepubgen.sourceforge.net/

Liberation fonts from Red Hat to replace MS TTF fonts

https://github.com/liberationfonts/liberation-fonts

Full-featured and high-performance event loop library

http://software.schmorp.de/pkg/libev.html

Linux Event Device library

https://www.freedesktop.org/wiki/Software/libevdev/

API for executing callback functions on events or timeouts

https://libevent.org/

Library for inspecting program's backtrace

http://www.gnu.org/software/libc/manual/html_node/Backtraces.html

Library to read digital camera file meta-data

https://libexif.github.io/

Application library for the Xfce desktop environment

https://www.xfce.org/

Video encoding library

http://fame.sourceforge.net/

Foreign Function Interface

https://sourceware.org/libffi/

C++ library for building platform-independent programs

https://lib.filezilla-project.org/

The fontenc Library

https://www.x.org/

Library routines for working with Flashpix images

https://www.i3a.org/

Library (using libusb) to talk to FTDI chips

http://www.intra2net.com/de/produkte/opensource/ftdi/

General purpose crypto library based on code used in GnuPG

https://www.gnupg.org/software/libgcrypt/index.html

Provides uniform access to different kinds of data sources

https://www.gnome-db.org/