Modern cross-platform port of the Descent engine

A modernization effort of DOOM-3-BFG

Dhewm 3 is a Doom 3 GPL source port

Open source first person shooter

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

Epic story-driven FPS running on the Build Engine

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

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

Source port for Build engine games

Fast paced, first person strategy game

Leading the way in newschool multiplayer Doom online

The Free and Fast Arena Shooter

EDuke32 is an awesome, free homebrew game engine

First-person shooter with cooperative in-game map editing

Classic arena first person shooter

Top-down shooter action RPG

FPS aim trainer

Game engine for Return to Castle Wolfenstein

Tank digging battle game

Open source first person shooter

The orb ponderer's arena first-person shooter

ReC98 source port of the first Seihou Project game

a modern QuakeWorld client focused on competitive online play

A Quake mod based on the retro shooter SPRAWL

Game engine for Classic Doom

First-person shooter game

Free fast paced arena shooter

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

Shoot and survive

Free agile arena shooter