Yo Frankie! (code-named Apricot) is an open source computer game by the Blender Institute, part of the Blender Foundation. It is based on the universe and characters of the open source film produced earlier in 2008 by the Blender Institute, Big Buck Bunny.
Yo Frankie! is licensed under the Creative Commons Attribution license 3.0. In short, this means you can freely reuse and distribute this content, also commercially, for as long you provide a proper attribution. The attribution is:
(c) copyright Blender Foundation | http://apricot.blender.org.