Fast and lightweight JavaScript game engine built on WebGL and glTF
Unity3D Client And C# Server Framework
You can make it - Open Source MMORPG Platform
Open source HTML5 game framework that offers WebGL and Canvas
Desktop/Android/HTML5/iOS Java game development framework
Open source library for N64 development
Open source library for creative expression on the web, desktop, etc.
JavaScript framework to build game engines, games, emulators and apps
Molecular viewer and prototyping framework
2D Game Engine
The imaginary eight-bit machine
A complete web framework to create online Fighting Fantasy adventures
X3D Prototypes for the SMUOS Component
Free strategy browsergame engine.
a game library to develop audio games
AutoTeach makes kids study and learn in exchange for internet access.
Java Gamepad API for multiple platforms
Multi-threaded 2D Renderer licensed under the Mozilla Public License
TurboSphere is an easy to learn and powerful JS based game engine.
Modular Gaming Open Source Persistent Browser Based Game Framework
A lightweight HTML5 Game Engine
C-Lesh is a game programming language for 2D games.
An extensible development framework for roleplay games.