Blitz3D - Create 2D and 3D Games for Windows.
BlitzMax NG - Fast cross-platform, open-source, programming language.
BlitzPlus - Create 2D Games for Windows.
Monkey 2 - An easy to use, cross platform, games oriented programming language
Godot Engine - Feature-packed 2D and 3D open source game engine.
AppGameKit - AppGameKit is a game development platform for mobile devices.