Godot is a powerful cross-platform game engine
Fast and lightweight JavaScript game engine built on WebGL and glTF
Flax Engine, multi-platform 3D game engine
Xash3D FWGS engine
Cocos simplifies game creation and distribution with Cocos Creator
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
The flexible game engine
Cross-Platform C++ 2D/3D game engine
Cross-platform 2D and 3D game engine with modular architecture
Multi-platform 2D and 3D game engine
Zig game engine & graphics toolkit
An OpenGL RTS game engine written in C
A grid based movement engine compatible with Phaser3
A game engine with an emphasis on real-time cutting-edge solutions
Solar2D Game Engine main repository (ex Corona SDK)
GZDoom is a feature centric port for all Doom engine games
Open 3D Engine (O3DE) is an Apache 2.0-licensed multi-platform 3D
UCI chess engine
A modern cross-platform low-level graphics library
Open source voxel game engine with support for survival and crafting
Unreal Engine Archives Explorer
LayaAir is an open-source 2D/3D engine
A complete 3-D game development suite written in Java
Scripting platform, modding framework and VR support for RE Engine
UZDoom is a feature centric port for all Doom engine games