Godot is a powerful cross-platform game engine
Stream switch games to your PC via USB or network
A simple and easy-to-use library to enjoy videogames programming
A cross-platform PSP emulator
Xash3D FWGS engine
UCI chess engine
Open source voxel game engine with support for survival and crafting
Do virtual gear shifting (and more) in any rider app
Desktop/Android/HTML5/iOS Java game development framework
RetroArch is a frontend for emulators, game engines and media players.
One framework for creating powerful cross-platform games
Open-source Android/Desktop remake of Civ V
The game engine for everyone
Sandbox video game with a powerful physics engine
Home theater software and entertainment hub for digital media
Open source cross-platform multi-purpose game toolkit
The source code to VVVVVV
Open source HTML5 game framework that offers WebGL and Canvas
Voxel game-creation platform with easy modding and game creation
Multi-platform 2D and 3D game engine
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
An iOS & tvOS Frontend for Multiple Emulators
Netcode that provides networking capabilities to GameObject workflows
Free, cross-platform 2D game engine powered by Haxe and OpenFL