You can make it - Open Source MMORPG Platform
Godot is a powerful cross-platform game engine
Desktop/Android/HTML5/iOS Java game development framework
Open Source MMORPG Framework
One framework for creating powerful cross-platform games
A simple and easy-to-use library to enjoy videogames programming
A game framework written with osu! in mind.
Self-hosted CMS platform based on the Laravel PHP Framework
Real Time Strategy game engine supporting early Westwood classics
Open source library for creative expression on the web, desktop, etc.
Gideros Release version
All-In-One program that combines multiple Fortnite Dev Account tools.
INSTEAD - Simple Text Adventure Interpreter.
Game engine supporting many 3D/2D formats and graphic effects
JavaScript framework to build game engines, games, emulators and apps
2D Game Engine
FreeCS is a free-software reimplementation of Counter-Strike 1.5.
A cross platform Lua based game engine
A real-time game development platform
Cross-platform 2D and 3D game engine
Example code for creating a 2D platform game in Java.
A synchronisation component for p5.js
Build Cross-platform Applications