Box2D v2.0.2 User ManualBox2D is a 2D rigid body simulation library for games. Programmer's can use it in their games to make objects move in believable ways and make the world seem more interactive. From the game's point of view a physics engine is just a system for procedural animation. Rather than paying (or begging) an animator to move your actors around, you can let Sir Isaac Newton do the directing.Box2D is written
http://www.simplesystems.org/RMagick/doc/
