dhewm 3 main repository
Xash3D FWGS engine
Real Time Strategy game engine supporting early Westwood classics
A modern, cross-platform Quake game engine based on FitzQuake.
GemRB is a portable open-source implementation of the Infinity Engine
Game engine supporting many 3D/2D formats and graphic effects
API (C#) for simulating certain aspects of a ZX spectrum for porting.
Embeddable unity game engine view for Flutter
Spring is a free RTS engine developed for Windows, Linux and Mac OS X.
Go 3D Game Engine
A cross platform Lua based game engine
2D physics engine for games