Bullet is a 3D Collision Detection and Rigid Body Dynamics Library for games and special effects for film and animations. Bullet is integrated into many 3d modelers including Maya, Houdini, Cinema 4D, LightWave and Blender. It is free for commercial use and open source under the permissive ZLib License.

Bullet is cross-platform for Windows, Linux, Mac OSX, Playstation 3, XBox 360, Wii, iOS, Android with special optimizations for x86 SIMD SSE, Cell SPE and OpenCL.