Xash3D FWGS engine
The ioquake3 community effort to continue supporting/developing id's
The flexible game engine
An OpenGL RTS game engine written in C
Go bindings for raylib, a simple and easy-to-use library
3D game engine/framework in C, with Luajit and Python bindings now
A modern, cross-platform Quake game engine based on FitzQuake.
Orx: Portable Game Engine
SDL based generic 2D game engine
A completely free, open-source, 2D game engine
An authentic Rise of The Triad Dark War source port
A simple math library for games and computer graphics
A conservative source port of Hexen that is identical to DOS
A conservative source port of Heretic that is identical to DOS
A cross-platform, open-source, pure C game engine for mobile game
Game engine to build text adventures.
Retro game engine for creating games like it's 1997
A fork of Chocolate Doom with small Quality of Life enhancements
Conservative port of BOOM 2.02 to modern systems.
a UCI chess engine
DOOM / Heretic / Hexen source port with enhanced graphics and UI
Cross-platform 2D and 3D game engine
Low-Level Game Engine for Retro Platforms
Game engine for playing tomb raider 1 - 5 levels.