Blender is a free open source 3D content creation suite, available for all major operating systems under the GNU General Public License.
This is a fully-loaded upgrade of Blender including many game engine improvements (video textures, real-time dome rendering, a Bullet physics upgrade, an improved Python API and a hand full of overall speedups), the long awaited texture nodes, direct painting of textures on your 3D objects, improved boolean operations, JPEG2000 support and Etch-a-ton, a sketching technique for rigging.