Common interface to speech synthesis

http://devel.freebsoft.org/speechd

CLI and Go API to test internet speed using speedtest.net

https://github.com/showwin/speedtest-go

open-source patent-free voice codec

http://www.speex.org/

Audio compression format designed for speech

http://www.speex.org/

Sphinx Full-Text Search Engine

http://sphinxsearch.com/

Gtk client and libraries for SPICE remote desktop servers

http://www.spice-space.org/

Simple Protocol for Independent Computing Environments

http://www.spice-space.org

Standalone JavaScript based from Mozilla 102-esr

https://spidermonkey.dev/

Standalone JavaScript based from Mozilla 128-esr

https://spidermonkey.dev/

Standalone JavaScript based from Mozilla 91-esr

https://spidermonkey.dev/

Bi-directional translation between SPIR-V and LLVM IR

https://github.com/KhronosGroup/SPIRV-LLVM-Translator

Tools for processing SPIR-V intermediate shader language modules

https://github.com/KhronosGroup/SPIRV-Tools

Monospaced bitmap fonts for Xorg and vt(4)

https://github.com/fcambus/spleen

Tool for statically checking sourcecode for security vulnerabilities

http://www.splint.org/

Japanese custom font based on Noto Sans and Lato

https://github.com/spoqa/spoqa-han-sans

The Spring Framework for Java

http://www.springframework.org/

Double entry accounting system

http://www.sql-ledger.org/

Lightweight database abstraction layer

SQLite backed FUSE file system

https://www.nongnu.org/libsqlfs/

SQL database engine in a C library

http://www.sqlite.org/

SQL database engine in a C library

https://www.sqlite.org/

Set of tools to manipulate squashfs images

https://squashfs.sourceforge.net/

New set of tools and libraries to work with SquashFS images

https://infraroot.at/projects/squashfs-tools-ng/

Mount a squashfs archive and treat it like a local file system

https://github.com/vasi/squashfuse

HTTP Caching Proxy

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

Webmail system which accesses mail over IMAP

http://www.squirrelmail.org/

Library for serialising LV2 atoms to/from RDF

http://drobilla.net/software/sratom

Supplement file for lookup to use "Random House"

http://openlab.ring.gr.jp/edict/srd-fpw/

Secure Reliable Transport (SRT) Protocol

https://www.srtalliance.org/

Tool for computing context triggered piecewise hashes

https://ssdeep-project.github.io/ssdeep/

Chat over SSH

https://github.com/shazow/ssh-chat

Mount remote directories over ssh

https://github.com/libfuse/sshfs

Protect hosts from brute-force attacks against SSH and other services

https://www.sshguard.net/

Non-interactive ssh password auth tool

https://sourceforge.net/projects/sshpass/

State Threads Library for Internet Applications

http://state-threads.sourceforge.net/

Library that supports startup notification spec from freedesktop.org

https://www.freedesktop.org/wiki/Software/startup-notification/

Stb single-file public domain libraries for C/C++

https://github.com/nothings/stb/

Generates C++ and Python from ISO10303 files

https://github.com/stepcode/stepcode/wiki

Monospace font created for the French magazine Etapes

https://raphaelbastide.com/steps-mono

OpenType Unicode fonts for Scientific, Technical, and Math texts

http://www.stixfonts.org/

Synthesis ToolKit in C++

https://ccrma.stanford.edu/software/stk

Command-line utility that pipes video streams

https://streamlink.github.io/

Stuffit Archive Creator and Expander

http://my.smithmicro.com/unix/stuffit/

Advanced IP/IPv6 subnet calculation and discovery

http://www.seccuris.com

Version control system

http://subversion.apache.org/

Version control system, long-time-support version

http://subversion.apache.org/

Receives/sends news to/from localhost via NNTP

https://github.com/lazarus-pkgs/suck

Allow others to run commands as root

https://www.sudo.ws/

Font for programmers and command line users

https://www.kutilek.de/sudo-font

C library for loading and wrapping LV2 plugin UIs

http://drobilla.net/software/suil/