First-person shooter game

Game engine for Return to Castle Wolfenstein

Leading the way in newschool multiplayer Doom online

Classic arena first person shooter

Source port for Build engine games

Aliens vs Humans, First Person Shooter game with elements of Real Time Strategy

The Free and Fast Arena Shooter

Fast paced, first person strategy game

Shoot and survive

A modernization effort of DOOM-3-BFG

Free agile arena shooter

dhewm 3 is a Doom 3 GPL source port

Nowoczesna wieloplatformowa konwersja „STAR WARS™: Dark Forces” z obsługą modyfikacji

Tank digging battle game

Free fast paced arena shooter

Open Source voxel shooter

Game engine for Classic Doom

Open source first person shooter

A Quake mod based on the retro shooter SPRAWL

Top-down shooter action RPG

Yamagi Quake II is an alternative client for id Software's Quake II

Epic story-driven FPS running on the Build Engine

EDuke32 is an awesome, free homebrew game engine

Open source first person shooter

FPS aim trainer

Modern cross-platform port of the Descent engine

The orb ponderer's arena first-person shooter

A Zandronum 3.0 fork with improved netcode, configurable movement and many small tweaks

ReC98 source port of the first Seihou Project game

First-person shooter with cooperative in-game map editing