A game engine powered by python and panda3d
3D game engine/framework in C, with Luajit and Python bindings now
utility collection for 2D game development in Java; sound-player
Zig game engine & graphics toolkit
Game engine supporting many 3D/2D formats and graphic effects
GemRB is a portable open-source implementation of the Infinity Engine
A modern, cross-platform Quake game engine based on FitzQuake.
Full featured MUD server with all the trimmings.
C++ lightweight cross-platform game engine
The multiplayer game engine
Spring is a free RTS engine developed for Windows, Linux and Mac OS X.
DOOM / Heretic / Hexen source port with enhanced graphics and UI
Opensource Game Studio
Portable game engine with main focus on point-and-click adventures
Web powered cross-platform 3D, WebXR game engine
A 3D game engine in java.
An advanced flexible game engine for Java.
An online multiplayer turn based strategy game and board game engine.