NodeBox for OpenGL
http://cityinabottle.org/nodebox

The game development engine. A free, cross-platform library for generating 2D animations with Python programming code. It is built on Pyglet and adopts the drawing API from NodeBox for Mac OS X (http://nodebox.net). It has built-in support for paths, layers, motion tweening, hardware-accelerated image effects, simple physics and interactivity.

Documentation can be found here →