Chess Database and PGN viewer
For exploring cellular automata like Conway's Game of Life.
A modern, cross-platform Quake game engine based on FitzQuake.
Colonize the New World.
Good-looking and addictive OpenSource games
Open and edit the archive files used in over 4200 games.
A standalone UQM mod made to enhance gameplay and visuals
Nestopia UE
Seven Kingdoms: Ancient Adversaries
A cross-platform port of Hexen II game.
Odamex is a free, cross-platform, modern client-server Doom engine
A very richly featured implementation of the Sokoban puzzle game