The flexible game engine
Godot is a powerful cross-platform game engine
Solar2D Game Engine main repository (ex Corona SDK)
A complete 3-D game development suite written in Java
Voxel game-creation platform with easy modding and game creation
Powerful, mature open-source cross-platform game engine for Python
Cross-platform 2D game engine focused on ultimate productivity
Cross-platform 2D and 3D game engine with modular architecture
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
Multi Theft Auto is a game engine
Stride (formerly Xenko), a free and open-source cross-platform C# game
KorGE Game Engine. Multiplatform Kotlin Game Engine & Korlibs
Cocos simplifies game creation and distribution with Cocos Creator
Real Time Strategy game engine supporting early Westwood classics
Free game engine for development of desktop, mobile, and web games
The game engine for everyone
Open source clone of the Age of Empires II engine
Xash3D FWGS engine
Cross-platform game engine in Rust
Recreation of the classic Grand Theft Auto III game executable
A game framework written with osu! in mind.
A game engine powered by python and panda3d
Kotlin extensions for the libGDX game framework
A completely free, open-source, 2D game engine
3D Procedural Game Engine Using OpenGL