Godot is a powerful cross-platform game engine
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
Multi-platform 2D and 3D game engine
Cocos simplifies game creation and distribution with Cocos Creator
Fast and lightweight JavaScript game engine built on WebGL and glTF
The flexible game engine
Xash3D FWGS engine
Solar2D Game Engine main repository (ex Corona SDK)
Flax Engine, multi-platform 3D game engine
JavaScript-based game engine designed to empower developers
The game engine for everyone
A JavaScript engine optimized for running React Native
GemRB is a portable open-source implementation of the Infinity Engine
Cross-platform 2D and 3D game engine with modular architecture
New Godot bindings for Swift
Cross-Platform C++ 2D/3D game engine
A dead simple 2D game engine for Go
An OpenGL RTS game engine written in C
Simple and light-weight 3D game engine
V1, Mirror Classic. V2, Mirror Engine: Join Discord for access
A game engine with an emphasis on real-time cutting-edge solutions
Zig game engine & graphics toolkit
An open-source sandbox tower defense game
A certain block game
A complete 3-D game development suite written in Java