And yes, anyone is allowed to host their own (possibly modified) version of the online modeling tool. There is a package of version 0.91 available for download, or you can pull the source from the CVS if you want a fresher version, i.e. 0.92. It is described on Google Code how to download a working copy from the repository.
Note that I usually never check in anything that breaks functionality, but the source is a moving target and may of course contain not yet known bugs.