Blender

Blender is a free software 3D animation program. It can be used for modeling, UV unwrapping, texturing, rigging, skinning, animating, rendering, particle simulating, non-linear editing, compositing, and creating interactive 3D applications. Blender is available for several operating systems, including Microsoft Windows, Mac OS X, Linux, IRIX, Solaris, NetBSD, FreeBSD, OpenBSD with unofficial ports for BeOS, SkyOS, MorphOS and Pocket PC. Blender has a robust feature set similar in scope and depth to other high-end 3D software such as Softimage|XSI, Cinema 4D, 3ds Max, Lightwave and Maya. These features include advanced simulation tools such as rigid body, fluid, and softbody dynamics, modifier based modeling tools, powerful character animation tools, a node based material and compositing system and Python for embedded scripting.