Box2D: Box2D (2D Games Physics Engine) Box2D: Box2D: Box2D is an open source C++ engine for simulating rigid bodies in 2D Box2D: Box2D is developed by Erin Catto and has the zlib license. While the Box2D: zlib license does not require acknowledgement, we encourage you to Box2D: give credit to Box2D in your product. Box2D: Box2D: Box2D: Box2D: Box2D: