Open source first person shooter

Shoot and survive

Open source first person shooter

First-person shooter game

Free fast paced arena shooter

FPS aim trainer

First-person shooter with cooperative in-game map editing

A Quake mod based on the retro shooter SPRAWL

EDuke32 is an awesome, free homebrew game engine

Modern cross-platform port of the Descent engine

A modern cross‑platform port of “STAR WARS™: Dark Forces” with mod support

Tank digging battle game

The orb ponderer's arena first-person shooter

ReC98 source port of the first Seihou Project game

Epic story-driven FPS running on the Build Engine

Top-down shooter action RPG

Game engine for Return to Castle Wolfenstein

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

Source port for Build engine games

Classic arena first person shooter

A modernization effort of DOOM-3-BFG

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

Open Source voxel shooter

Free agile arena shooter

a modern QuakeWorld client focused on competitive online play

Fast paced, first person strategy game

Leading the way in newschool multiplayer Doom online

Fast arcade first person shooter

Open Source voxel shooter

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