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

https://libclc.llvm.org/

Alternative configuration system for Compiz

Simple library for manipulating structured configuration files

http://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)

http://seahorse.sourceforge.net/

CUE Sheet Parser Library

http://sourceforge.net/projects/libcue/

Lightweight C library that eases the writing of UNIX daemons

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

Double-array trie implementation library

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

Companion library to GObject and GTK

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

Free DTS Coherent Acoustics decoder

http://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

http://libdlna.geexbox.org/

Library for reading and writing Data Matrix barcodes

http://www.libdmtx.org/

DMX extension library

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

A simple interface to low level networking routines

https://code.google.com/p/libdnet/

Standard library for Window Maker dock apps

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

Userspace interface to kernel Direct Rendering Module services

http://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

http://www.videolan.org/libdvdcss

MPlayer version of the libdvdnav project

http://dvdnav.mplayerhq.hu

MPlayer version of the libdvdread project

http://dvdnav.mplayerhq.hu

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

http://www.mr511.de/software/

Enhanced Metafile Library

http://libemf.sourceforge.net/

epoll shim implemented using kevent

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://fedorahosted.org/liberation-fonts/

Full-featured and high-performance event loop library

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

Linux Event Device library

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

API for executing callback functions on events or timeouts

http://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

http://sourceforge.net/projects/libexif/

Application library for the Xfce desktop environment

http://www.xfce.org/

Video encoding library

http://fame.sourceforge.net/

Foreign Function Interface

http://sources.redhat.com/libffi/

C++ library for building platform-independent programs

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

The fontenc Library

http://www.x.org/

Library routines for working with Flashpix images

http://www.i3a.org/

A 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

http://www.gnupg.org/

Provides uniform access to different kinds of data sources

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