Godot is a powerful cross-platform game engine
An open-source sandbox tower defense game
A simple and easy-to-use library to enjoy videogames programming
Xash3D FWGS engine
A certain block game
UCI chess engine
One framework for creating powerful cross-platform games
Desktop/Android/HTML5/iOS Java game development framework
RetroArch is a frontend for emulators, game engines and media players.
Home theater software and entertainment hub for digital media
The game engine for everyone
Open source HTML5 game framework that offers WebGL and Canvas
Do virtual gear shifting (and more) in any rider app
Cocos simplifies game creation and distribution with Cocos Creator
An open source reimplementation of the Among Us Server
Free, cross-platform 2D game engine powered by Haxe and OpenFL
The source code to VVVVVV
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
Multi-platform 2D and 3D game engine
Netcode that provides networking capabilities to GameObject workflows
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
Action-adventure game originally released in 2013
Cross-platform game engine in Rust
A dead simple 2D game engine for Go
Open source library for creative expression on the web, desktop, etc.