Blitz3D - Create 2D and 3D Games for Windows.
Monkey 2 - An easy to use, cross platform, games oriented programming language
Phaser - Desktop and Mobile HTML5 game framework. A fast, free and fun open source framework for Canvas and WebGL powered browser games.
AppGameKit - AppGameKit is a game development platform for mobile devices.
Cocos2d-x - Cocos2d-x is an open-source and cross platform open source free 2D game engine for mobile game development known for its speed, stability, and easy of use
BlitzMax NG - Fast cross-platform, open-source, programming language.