Open source clone of the Age of Empires II engine
Solar2D Game Engine main repository (ex Corona SDK)
Powerful, mature open-source cross-platform game engine for Python
Multi Theft Auto is a game engine
Free game engine for development of desktop, mobile, and web games
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
3D Game engine with editor
dhewm 3 main repository
Multi-platform 2D and 3D game engine
Recreation of the classic Grand Theft Auto III game executable
Descent 3 by Outrage Entertainment
Flax Engine, multi-platform 3D game engine
3D Procedural Game Engine Using OpenGL
GemRB is a portable open-source implementation of the Infinity Engine
Vivid3D is a C++ IDE/3D engine, with python scripting.
Orx: Portable Game Engine
Modified source engine (2017) developed by valve and leaked in 2020
Urho3D Game engine
Mini game engine for games104
A fork of dhewm3 with an emphasis on modernisation and vanilla Doom 3
Spring is a free RTS engine developed for Windows, Linux and Mac OS X.
DOOM / Heretic / Hexen source port with enhanced graphics and UI
3D C++ Game Engine - yet another open source game engine
Improved version of the X-Ray Engine, the game engine