3D game engine/framework in C, with Luajit and Python bindings now
Framework to facilitate communication in the Unity game engine
Open-source full-stack web development framework built on top of React
Arianne is an engine to develop multiplayer online games like Stendhal
A complete framework for Godot to create beautiful and complex AI
a 2D Game Development Framework
Build Cross-platform Applications
Game engine allows you to create own MMORPG
3D .NET engine for Windows, Linux, Mac
Modular Gaming Open Source Persistent Browser Based Game Framework
BxEngine For Marmalade And QT
Cross platform 2D game creation framework with Python bindings
Formerly CraveJs, it's for creating JavaScript applications and games.
Create your own online real-time browser-based MMO in your website
C++ SDL/Box2d Programming
A generic framework for the generation of game levels.