The flexible game engine
Godot is a powerful cross-platform game engine
Solar2D Game Engine main repository (ex Corona SDK)
An OpenGL RTS game engine written in C
Fast and lightweight JavaScript game engine built on WebGL and glTF
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
A game engine powered by python and panda3d
Cross-platform 2D and 3D game engine with modular architecture
Multi-platform 2D and 3D game engine
Flax Engine, multi-platform 3D game engine
Cross-Platform C++ 2D/3D game engine
Animation engine for explanatory math videos
Cocos simplifies game creation and distribution with Cocos Creator
A game engine with an emphasis on real-time cutting-edge solutions
Xash3D FWGS engine
Simple and light-weight 3D game engine
Zig game engine & graphics toolkit
Powerful, mature open-source cross-platform game engine for Python
Injectable LUA scripting system, SDK generator, live property editor
OpenDILab Decision AI Engine
3D Engine with Blender Integration
Open source clone of the Age of Empires II engine
A complete 3-D game development suite written in Java
GemRB is a portable open-source implementation of the Infinity Engine
The Ren'Py Visual Novel Engine