Carrington has always been Open Source (GPL), and now it is more transparent as it is hosted on Google Code.
The project has been reorganized so that the core framework can be an svn:external for the themes hosted there. Unfortunately Google makes you choose between https (accessible by project members) and http (public) for svn:externals, so that’s less than ideal. But it’s better than hosting it internally at Crowd Favorite.
With public hosting everyone has access in incremental enhancements and fixes as they happen.