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