Created by Bfurt Wangler, Box2D.XNA is a C#/XNA port of Box2D. It is optimized for the Xbox 360, minimizing allocations per frame and CPU time. Both the core engine and all test cases are ported including an XNA renderer. This download also includes an example demo project created by Nguy?n Ðan Tru?ng and the game Moto Trial Racer. Updated by Tomi Paananen, Moto Trial Racer is a motorcycle racing game on Windows Phone 7 & XNA Game Studio 4.0, demonstrating especially the use of Box2D.XNA. This application has been ported from corresponding Qt/QML example, and thereby also demonstrates and provides guidance on the porting and co-development between Qt and Windows Phone.