Odamex is a free, cross-platform, modern client-server Doom engine
A free 3d game for PC that does not limit the player. Fight,Build,Gain
DOOM / Heretic / Hexen source port with enhanced graphics and UI
Bot for id Software's Wolfenstein 3D
Quake C mods and support - SSQC / CSQC
AssaultCube is a FREE, multiplayer, first-person shooter game.
Cross platform administration tool for Source Engine dedicated servers
A QuakeWorld package containing everything needed to play QW right now
A fun-filled new take on the casual first person arena shooter.
A Co-op/Deathmatch Mod for half-life 2
Experimental raycasting engine