The build utility of the Qt project

http://www.trolltech.com/products/qt/index.html

Qt Makefile generator

http://qt-project.org

A command line program to query game servers on the net

http://www.qstat.org/

Qt Documentation

http://qt.nokia.com/products/qt/index.html

Qt Resource compiler

http://qt-project.org

Qt user interface compiler

http://qt-project.org

Quake III Arena data files

http://www.idsoftware.com/games/quake/quake3-arena/

Test performance of storage devices

Randr extension headers

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

File archiver (binary port)

https://www.rarlab.com/

Distributed, collaborative, spam detection and filtering network

http://razor.sourceforge.net/

Unix incarnation of the plan9 shell

http://tobold.org/article/rc

Checks rc scripts for style and common errors

https://github.com/crees/rclint

Lexer generator for C, C++ and Go with a focus on generating fast code

https://re2c.org/

Library for editing command lines as they are typed

https://tiswww.case.edu/php/chet/readline/rltop.html

RECORD extension headers

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

RenderProto protocol headers

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

Resource extension headers

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

A fast redirector and access controller for squid

http://www.bsdnexus.com/retsina/index.htm

Restricted Secure SHell only for sftp or/and scp

http://www.pizzashack.org/rssh/index.shtml

Network file distribution/synchronization utility

http://rsync.samba.org/

Kernel module which provides /dev/rtc device support

A set of tools to record, playback and monitor RTPv2 data streams

nsupdate utility with the GSS-TSIG support

https://www.isc.org/software/bind

Stand-Alone shell combining many common utilities

http://members.tip.net.au/~dbell/

Scan_ffs recovers lost disklabel

ANSI C version of the SciMark2 benchmark

https://math.nist.gov/scimark2/download_c.html

Build tool alternative to make

https://scons.org/

Tiny shell that only permits scp and sftp

https://github.com/scponly/scponly/wiki

Converts the output of "vidcontrol -p" to text

Multi-screen window manager

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

Small and lightweight screen(1) wrapper

https://sourceforge.net/projects/screenie/

ScrnSaver extension headers

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

"Simplified" DocBook XML DTD

http://www.oasis-open.org/docbook/xml/simple/

A utility for generating secure passphrases

http://www.core-dump.com.hr/?q=node/28

Extensive german HTML reference

http://www.selfhtml.org/

Reliable, highly configurable mail transfer agent with utilities

https://www.sendmail.org/

Interoperability between desktops and collaborative environments

http://oscaf.sourceforge.net

Generic script compiler

http://www.datsi.fi.upm.es/~frosal/frosal.html

Font dumper for the X font server

https://www.x.org/

HTTP regression testing and benchmarking utility

http://www.joedog.org/JoeDog/Siege

Small (150k), fast, perl-based IRC client

http://www.iagora.com/~espel/sirc.html

P2P VoIP software

http://www.skype.net/

Fast compressor/decompressor library

http://google.github.io/snappy/

Traps spammers with a very slow smtp-login and return 4xx error

http://freebsdspamd.sourceforge.net/

Spawns fastcgi applications

http://redmine.lighttpd.net/projects/spawn-fcgi

Voice communication over data networks

http://speak-freely.sourceforge.net/

open-source patent-free voice codec

http://www.speex.org/

SQL database engine in a C library

https://www.sqlite3.org/

HTTP Caching Proxy

http://www.squid-cache.org/