Versioning info for schema.org?

Hi!

I was wondering if you recorded different versions or versioning info for schema.org<http://schema.org>?  If so, where can I download different versions or this versioning info?  Thanks!
joe



Joseph T. Tennis
Assistant Professor
The Information School
University of Washington

Reviews Editor for the journal Knowledge Organization

jtennis@uw.edu<mailto:jtennis@uw.edu>
http://ischool.uw.edu/people/faculty/jtennis