Open source (175)

Snarf

Shooter, 1988
Shareware (installed), Shareware, Freeware

Sopwith

Shooter, 1984
Freeware (installed), Freeware, Source code

Sopwith (The Author's Edition)

Shooter, 2003
Freeware (installed), Freeware, Source code

Space Plumber

Puzzle, 1997
Freeware, Freeware, Source code

Speed Haste

Racing, 1995
Shareware

Star Control II

Also known as Star Control II: The Ur-Quan Masters, Star Control 2

Adventure, 1992
Playable demo

Station Escape

Adventure, 1993
Freeware (installed), Freeware, Source code

Stellar Conquest III

Also known as Stellar Conquest ]I[, Stellar Conquest III, Hostile Takeover

Turn-Based Strategy, 1994
Shareware, Source code

Sudoku86

Also known as Sudoku

Traditional, 2015
Freeware

Supernova

Adventure, 1986
Full version

TecnoballZ

Arcade, 1992
Full version (installed), Full version

TerraScape - Breakdown Velocity

Shooter, 2003
Freeware (installed), Freeware, Source code

Tetris (Alchemic)

Puzzle, 2004
Freeware

Tetris (Johan Peitz)

Puzzle, 1997
Freeware, Source code

Tic-Tac-Toe

Traditional, 2014
Freeware

Triplane Turmoil

Shooter, 1996
Full version