Godot is a powerful cross-platform game engine
The Ren'Py Visual Novel Engine
Xash3D FWGS engine
Open source voxel game engine with support for survival and crafting
Real Time Strategy game engine supporting early Westwood classics
A game engine powered by python and panda3d
fheroes2 is a recreation of Heroes of Might and Magic II game engine
A complete 3-D game development suite written in Java
The game engine for everyone
Solar2D Game Engine main repository (ex Corona SDK)
Multi Theft Auto is a game engine
Open-source engine for Heroes of Might and Magic III
Fast and lightweight JavaScript game engine built on WebGL and glTF
Voxel game-creation platform with easy modding and game creation
Powerful, mature open-source cross-platform game engine for Python
Cross-Platform C++ 2D/3D game engine
Cocos simplifies game creation and distribution with Cocos Creator
Cross-platform 2D and 3D game engine with modular architecture
Open 3D Engine (O3DE) is an Apache 2.0-licensed multi-platform 3D
Voxel game engine in C++ with OpenGL
The ioquake3 community effort to continue supporting/developing id's
Descent 3 by Outrage Entertainment
A refreshingly simple data-driven game engine built in Rust
Open source clone of the Age of Empires II engine
The flexible game engine