Powerful, mature open-source cross-platform game engine for Python
Open source clone of the Age of Empires II engine
A retro game engine for Python
Pycraft is an open-source, OpenGL based game made in Python
3D game engine/framework in C, with Luajit and Python bindings now
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
Free, open source game engine online
GemRB is a portable open-source implementation of the Infinity Engine
Vivid3D is a C++ IDE/3D engine, with python scripting.
A game engine for console based text games
DOOM / Heretic / Hexen source port with enhanced graphics and UI
Python ctypes module for the Irrlicht Engine SDK
KlayGE is a cross-platform open source game engine
The second demo of my game engine.
Open source, moddable game engine for the "Polygon Love 2" game
Tactical, turn-based game engine, that uses OpenGL and WinAPI
Scripting language of the hawk game engine
Browser game engine