The Blender Foundation initiated this Open Source movie project and it follows the 2007 released Elephants Dream. The Blender Foundation and Blender community have been the main financiers for Peach.
Until now a DVD was sold with the Big Buck Bunny to raise money for the next Open source animated movie. The DVD is still available if you want to support this effort. You can also donate here.
I watched Big Buck Bunny and it is really nice and has very funny moments. Big Buck Bunny is available for download in various formats or streaming on this page.