Godot is a powerful cross-platform game engine
Xash3D FWGS engine
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
Cocos simplifies game creation and distribution with Cocos Creator
Multi-platform 2D and 3D game engine
UCI chess engine
Zero Hour running natively on macOS, iPhone & iPad
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
The game engine for everyone
A dead simple 2D game engine for Go
New Godot bindings for Swift
An iOS & tvOS Frontend for Multiple Emulators
Free, cross-platform 2D game engine powered by Haxe and OpenFL
3D Engine c++
GemRB is a portable open-source implementation of the Infinity Engine
Home theater software and entertainment hub for digital media
Cross-platform game engine in Rust
Orx: Data-Driven Game Engine
A Complete WebGPU Game Engine for Browser & Desktop Arcade Oriented
GLScene Engine for Delphi & C++Builder VCL Windows 32/64
Urho3D Game engine
The AWS GameKit Plugin for Unreal
Cinema Enters Game Console
2D Game Engine