Blender the free open source 3D content creation suite.
Blender is the free open source 3D content creation suite, available for all major operating systems under the GNU General Public License.
Blender is an alternative to very expensive animation softwares, for learning and bussiness purposes and to produce high level animations.
See it on comparison chart at http://www.tdt3d.be/articles_viewer.php?art_id=99
Tutorials : http://www.tutsbuzz.com/tutorials/blender3d.html