Blender
Blender is the free and open source 3D creation suite. It supports the entirety of the 3D pipeline-modeling, rigging, animation, simulation, rendering, compositing, motion tracking and video editing.
Project Pages
Development
License
Blender as a whole is licensed under the GNU General Public License, Version 3. Individual files may have a different, but compatible license.
See blender.org/about/license for details.