Godot is a powerful cross-platform game engine
Enables Roblox developers to use professional software tools
A simple and easy-to-use library to enjoy videogames programming
Desktop/Android/HTML5/iOS Java game development framework
One framework for creating powerful cross-platform games
Real Time Strategy game engine supporting early Westwood classics
Open source HTML5 game framework that offers WebGL and Canvas
Fast and lightweight JavaScript game engine built on WebGL and glTF
Open Source MMORPG Framework
CTFs as you need them
lua dev plugin for unreal engine 4 or 5
Self-hosted CMS platform based on the Laravel PHP Framework
A game framework written with osu! in mind.
Gideros Release version
ThinkPHP Framework
You can make it - Open Source MMORPG Platform
Open source library for N64 development
Unity3D Client And C# Server Framework
Open source library for creative expression on the web, desktop, etc.
All-In-One program that combines multiple Fortnite Dev Account tools.
Arianne is an engine to develop multiplayer online games like Stendhal
Game engine supporting many 3D/2D formats and graphic effects
INSTEAD - Simple Text Adventure Interpreter.
utility collection for 2D game development in Java; sound-player
Orx: Data-Driven Game Engine