The ftp mirror most likely has tarballs of the source of all recent versions. Any VCS would not give you the same protection, unless you assume that there are

The ftp mirror most likely has tarballs of the source of all recent versions. Any VCS would not give you the same protection, unless you assume that there are a bunch of developers that keep checkouts of every major version (with DVCS, that would certainly be the case. Otherwise? I don't think so.)