Windowing concept abstraction library for X11 and Wayland

https://gitlab.xfce.org/xfce/libxfce4windowing

Libraries for xine multimedia player

http://www.xine-project.org/

Keymap handling library for toolkits and window systems

https://xkbcommon.org/

XKB file library

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

Utility library to make XKB stuff easier

http://gswitchit.sourceforge.net/

XML API for C++

http://libxmlplusplus.sourceforge.net/

XML parser library for GNOME

http://xmlsoft.org/

Python interface for XML parser library for GNOME

http://xmlsoft.org/

Library to help create and query binary XML blobs

https://github.com/hughsie/libxmlb

Module rendering library for xmp

http://xmp.sourceforge.net/

XSD runtime library

https://www.codesynthesis.com/projects/xsd/

W3C XML Schema compiler frontend

https://www.codesynthesis.com/projects/libxsd-frontend/

Shared memory 'SyncFence' synchronization primitive

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

The XSLT C library for GNOME

http://xmlsoft.org/XSLT/

YAML 1.1 parser and emitter written in C

https://pyyaml.org/wiki/LibYAML

YANG data modeling language library, version 2

https://github.com/CESNET/libyang

Library for decrypting and parsing YubiKey One-Time Passwords

https://developers.yubico.com/yubico-c/

Library for freeswitch yuv graphics manipulation

https://chromium.googlesource.com/libyuv/libyuv/

GLib/GObject wrapper for the Skydrive and Hotmail API

https://github.com/GNOME/libzapojit

ZenLib used by MediaInfo and its library

https://mediaarea.net/en/MediaInfo https://github.com/MediaArea/ZenLib

Reference implementation of the ZIM specification

https://wiki.openzim.org/wiki/Libzim

C library for reading, creating, and modifying ZIP archives

https://libzip.org/

ZeroMQ core library (Version 4)

https://www.zeromq.org/

C client interface to Zookeeper server

https://zookeeper.apache.org/

GNU ZRTP library

https://github.com/wernerd/ZRTPCPP

Routines to access raw VBI capture devices

http://zapping.sourceforge.net/doc/libzvbi/

Simple RSS/RDF feed reader

https://lzone.de/liferea/

Gnome ligthsoff

https://wiki.gnome.org/Lightsoff

Secure, fast, compliant, and flexible Web Server

https://www.lighttpd.net/

Make use of LV2 plugins as simple as possible

https://drobilla.net/software/lilv

Modern, advanced, portable, multiprotocol bootloader and boot manager

https://limine-bootloader.org/

Rich city simulation game for X

http://lincity.sourceforge.net/

Digital version of Frederic Goudy's Deepdene

https://www.theleagueofmoveabletype.com/linden-hill

Lynx-like text WWW browser

http://links.twibright.com/

Lynx-like text WWW browser

http://www.jikos.cz/~mikulas/links/

Meta-port for all things CentOS 7.9.2009

https://centos.org

Advanced Linux Sound Architecture libraries (Linux CentOS 7.9.2009)

http://www.alsa-project.org/

Advanced Linux Sound Architecture headers (Linux CentOS 7.9.2009)

https://www.alsa-project.org/

OSS plugin for ALSA (Linux CentOS 7.9.2009)

http://www.alsa-project.org/

PulseAudio plugin for ALSA (Linux CentOS 7.9.2009)

http://www.alsa-project.org/

Advanced Linux Sound Architecture utilities (Linux CentOS 7.9.2009)

http://www.alsa-project.org/

Spelling checker with better logic than ispell (Linux CentOS 7.9.2009)

Assistive technology ATK bridge (Linux CentOS 7.9.2009)

https://gitlab.gnome.org/GNOME/at-spi2-atk

Assistive technology service provider interface (Linux CentOS 7.9.2009)

https://gitlab.gnome.org/GNOME/at-spi2-core

Accessibility Toolkit (Linux CentOS 7.9.2009)

Implementation of the Audio File Library (Linux CentOS 7.9.2009)

http://www.68k.org/~michael/audiofile/

Libraries for Avahi (Linux CentOS 7.9.2009)

http://www.avahi.org/

Vector graphics library Cairo (Linux CentOS 7.9.2009)

https://www.cairographics.org/

Common UNIX Printing System libraries

https://www.cups.org/

Tool for transferring files with URL syntax (Linux CentOS 7.9.2009)