A Zombies Game
A Marathon (first-person shooter) engine with enhanced features
A Java light, open source first person shooter,with editors.
Alien-Tec AutoScript CS:Source
MD2 (Quake2) Model Viewer
Doom, Heretic, Hexen & Strife Map Viewer
Quake Engine Map Viewer
Duke Nukem 3D Map Viewer
EDGE is an advanced DOOM source port
Place where to find modifications and add-ons for the Arma franchise.
Extendable editor for manipulating lumps in DOOM WAD files.
An open-source, multiplayer fps based on Cube 2 Engine.