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