"aahz" == aahz firstname.lastname@example.org writes:
aahz> I'd rather not rely on licensing of a closed-source system; aahz> one of the points made during the talk was that the Linux aahz> project had to scramble when they lost their Bitkeeper aahz> license
Python is unlikely to throw away its license in the same way, I should think. For additional security, you could try to negotiate a perpetual license on a particular version, or a license that required substantial notice (say, six months) for termination. I would imagine you could get them; the only reason for the vendor not to give them would be spite.
The problem with both of those options is the one that Martin already pointed out: negotiation takes effort. There are several good open source alternatives, one of which (svn) is well-established and gets excellent reviews for those goals it sets itself, which happen to be solving the problems (as opposed to missing features) of CVS. Why spend effort on negotiating licenses and preparing for potential vendor relationship problems, unless there's acknowledged need for features svn doesn't provide?