a modern QuakeWorld client focused on competitive online play

First-person shooter game

Epic story-driven FPS running on the Build Engine

Shoot and survive

First-person shooter with cooperative in-game map editing

The Free and Fast Arena Shooter

The orb ponderer's arena first-person shooter

Game engine for Classic Doom

Classic arena first person shooter

Fast paced, first person strategy game

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

Source port for Build engine games

Open Source voxel shooter

Leading the way in newschool multiplayer Doom online

Free agile arena shooter

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

FPS aim trainer

ReC98 source port of the first Seihou Project game

Free fast paced arena shooter

EDuke32 is an awesome, free homebrew game engine

Dhewm 3 is a Doom 3 GPL source port

Open source first person shooter

Open Source voxel shooter

Open source first person shooter

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

A free first person shooter for Mac, PC and Linux

Game engine for Return to Castle Wolfenstein

A Quake mod based on the retro shooter SPRAWL

Tank digging battle game

Modern cross-platform port of the Descent engine