Fonts from the SGI ProPack 1.4 (originally for Linux)

http://oss.sgi.com/projects/sgi_propack/

Generates groff and HTML from linuxdoc and docbook SGML documents

SGML parser

GLSL/HLSL to SPIR-V shader compiler

https://github.com/google/shaderc

Interoperability between desktops and collaborative environments

http://oscaf.sourceforge.net

MIME types database from the freedesktop.org project

https://www.freedesktop.org/wiki/Software/shared-mime-info/

Collection of shareware ATM fonts from the CICA archives

Pack, send, and unpack shell archives; synchronize via e-mail

http://www.gnu.org/s/sharutils/

Generic script compiler

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

Benchmark utility for POSIX shell comparison

https://github.com/shellspec/shellbench

Font dumper for the X font server

https://www.x.org/

xUnit based unit testing for Unix shell scripts

https://github.com/kward/shunit2/

HTTP regression testing and benchmarking utility

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

MacOS High Sierra like theme for GTK 3, GTK 2 and Gnome-Shell etc

https://github.com/vinceliuice/Sierra-gtk-theme

GPG/PGP Keyring Graph Generator

http://www.chaosreigns.com/code/sig2dot/

Sigar system information API

https://support.hyperic.com/display/SIGAR/Home

Command-line and D-Bus interface for Signal and libsignal-service-java

https://github.com/AsamK/signal-cli

FTS5 extension for signal_tokenizer

https://github.com/signalapp/Signal-FTS5-Extension

Create and verify cryptographic signatures

https://github.com/leahneukirchen/outils/

Signon OAuth 1.0 and 2.0 plugin for accounts-sso

https://gitlab.com/accounts-sso/signon-plugin-oauth2

D-Bus service performing user authentication

https://gitlab.com/accounts-sso/signond

Sigrok firmware

https://www.sigrok.org/wiki/Firmware

Cypress FX2 firmware for hardware logic analyzers

https://www.sigrok.org/wiki/Fx2lafw

Sigrok firmware extraction utilities

https://www.sigrok.org/wiki/Firmware

Secure Internet Live Conferencing (SILC) network toolkit

http://www.silcnet.org/

Parsing gigabytes of JSON per second

https://simdjson.org/ https://github.com/simdjson/simdjson/

Simple MTP fuse filesystem driver

https://github.com/phatina/simple-mtpfs

simple calendar and agenda application

http://wiki.gnustep.org/index.php/SimpleAgenda.app

C++ library providing a simple API to INI-style configuration files

https://github.com/brofield/simpleini

Extremely simple IRC client

http://www.suckless.org/programs/sic.html

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

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

Maintains remote websites, uses FTP or WebDAV to sync up w/ local copy

http://www.manyfish.co.uk/sitecopy/

Japanese input method, library part

Japanese input method, binary part

General purpose C libraries used by skarnet.org software

https://www.skarnet.org/software/skalibs/

The "meta-port" for the SKK Japanese-input software

http://openlab.jp/skk/

SKK dictionary from Wikipedia (Japanese edition)

https://github.com/tokuhirom/jawiki-kana-kanji-dict

Jisyo (dictionary) files for the SKK Japanese-input software

http://openlab.jp/skk/dic.html

CDB jisyo (dictionary) files for the SKK Japanese-input software

http://openlab.jp/skk/dic.html

Jisyo-tools for the SKK Japanese-input software

https://github.com/skk-dev/skktools

SKK-like Japanese input method for X11

http://skkinput2.sourceforge.jp/

SKK-like Japanese input method for X11

https://sourceforge.jp/projects/skkinput3/

Dictionary server for the SKK Japanese-input software

http://openlab.ring.gr.jp/skk/index.html

Japanese warehouse keeper sokoban game

https://apps.kde.org/skladnik/

Slack client for your terminal

https://github.com/erroneousboat/slack-term

SIMD Library for Evaluating Elementary Functions, vectorized libm

https://sleef.org

Tool for checking, and diagnosing DNS zones

Simple facade or abstraction for various logging frameworks

http://www.slf4j.org/

Graphical login manager for X11, derived from Login.app

https://sourceforge.net/projects/slim.berlios/

Theme pack for SLiM login app

http://slim.berlios.de/themes01.php