blender

Blender is the open source, cross platform suite of tools for 3D creation
model - shade - animate - render - composite - interactive 3d
Blender is the free open source 3D content creation suite, available for allmajor operating systems under the GNU General Public License.

•  Windows XP, Vista, 7
•  Mac OS X (PPC and Intel) Linux
•  FreeBSD
  Blender works on 32 and 64 bit systems