Godot is a powerful cross-platform game engine
Desktop/Android/HTML5/iOS Java game development framework
Open source HTML5 game framework that offers WebGL and Canvas
One framework for creating powerful cross-platform games
A simple and easy-to-use library to enjoy videogames programming
Open source library for creative expression on the web, desktop, etc.
Examples of procedural geometry for Unity3D C#
Orx: Portable Game Engine
A complete 2D/3D Arcade Game Engine for Browser (Blender compatible)
Cinema Enters Game Console
Sdk library for creating 2048 game in c#.
2D Game Engine
Cross-platform 2D and 3D game engine
Open-source, cross-platform, C++ game engine for creating 2D/3D games
3D .NET engine for Windows, Linux, Mac
Cross platform 2D/3D game engine written in C++11 & OpenGL ES 2/3
Cross-platform 2D game engine