I understand about having to keep a legacy perl around to support older apps, etc, and I don't have a problem with that. It just seems like a no-brainer to also have an additional up-to-date perl (i.e. a separate install) if you plan on using up-to-date scripts. Chances are very good that these new scripts weren't actually designed or tested on your legacy perl (i.e. you'll need to test/examine them). Having a separate perl seems a lot easier to me than examining every new script you put on the machine to make sure it's going to work with your legacy perl.