Godot is a powerful cross-platform game engine
Fast and lightweight JavaScript game engine built on WebGL and glTF
Cocos simplifies game creation and distribution with Cocos Creator
Flax Engine, multi-platform 3D game engine
An OpenGL RTS game engine written in C
A game engine with an emphasis on real-time cutting-edge solutions
Multi-platform 2D and 3D game engine
Cross-platform 2D and 3D game engine with modular architecture
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
Xash3D FWGS engine
Cross-Platform C++ 2D/3D game engine
The flexible game engine
Zig game engine & graphics toolkit
Solar2D Game Engine main repository (ex Corona SDK)
Open 3D Engine (O3DE) is an Apache 2.0-licensed multi-platform 3D
A complete 3-D game development suite written in Java
Open source voxel game engine with support for survival and crafting
LayaAir is an open-source 2D/3D engine
The Ren'Py Visual Novel Engine
Recreation of the classic Grand Theft Auto III game executable
A game engine powered by python and panda3d
Multi Theft Auto is a game engine
Descent 3 by Outrage Entertainment
Open-source engine for Heroes of Might and Magic III
fheroes2 is a recreation of Heroes of Might and Magic II game engine