Blender Portable is the open source software for 3D modeling, animation, rendering, post-production, interactive creation and playback (Blender is available for all major operating systems under the GNU General Public License).
Plus, it leaves no personal information behind on the machine you run it on, so you can take your Blender application wherever you go.
Blender therefore is fully free to use and distribute within any educational, professional or commercial environment. Artwork created with Blender - including python scripts - is the sole property of the creator.