The classic, refined DOOM source port. For Windows PC.

Crispy Doom is a limit-removing enhanced-resolution Doom source port based on Chocolate Doom.

Advanced and featureful Rise of the Triad source port for modern systems

ET: Legacy is an open source project based on the code of Wolfenstein: Enemy Territory which was released in 2010 under the terms of the GPLv3 license.

Chocolate Doom is a Doom source port that is minimalist and historically accurate.

The ioquake3 community effort to continue supporting/developing id's Quake III Arena

A minimalist 3D raycasting engine built in C at 42, rendering a simple world from scratch with precision and speed.

A purist Quake source port that restores the original look and feel of v1.09 and earlier.

Modular Image processing Library toolKit (milk) 🔭

A 'C Software Rendered Game Engine' specifically for development of a fast paced, 3D shooter game.

µStreamer - Lightweight and fast MJPEG-HTTP streamer

Port of the original 1996 game from Ambrosia Software.

A Tremulous mod with enhanced gameplay, improved visuals, and extended customization.

A C99 3D game engine

Forsaken game engine

Shockolate - A minimalist and cross platform System Shock source port.

Linux framebuffer DOOM port

RtcwPro - Competition Mod for Return to Castle Wolfenstein

A First Person Shooter based on the Quake 3 engine.

Forked from Ozkan Sezer's repository. Has some tweaks and hacks here and there that I like to use.