[Zope] Python products - Versions in Zope

How do you guys manage versions in Python products on running sites? Do you have several versions of products running at the same time, or do you build in some kind of upgrade path that upgrades instanciated objects? Just looking for clues. regards Max M Max M. W. Rasmussen, Denmark. New Media Director private: maxmcorp@worldonline.dk work: maxm@normik.dk ----------------------------------------------------- Shipping software is an unnatural act