I've never really thought about how I would define "master": I'd probably get into the same argument I do with Perl certification. ;)

I certainly don't think there is one level of mastery. We might separate Perl programmers (or any programmers) into three rough cuts of beginner, intermediate, and advanced, but then we could go into each of those groups and cut each into three more groups.

I think the heart of the matter, however, if that a Perl master bends Perl to his will, rather than being limited by it. Damian, king of source filters and Perl magic, makes Perl does what he wants instead of the other way around, for instance.

Maybe the definition is just a subjective comparison, and everyone puts different labels on people. I think most people would agree that Autrijus, Randal, Damian, and Larry are masters. People can also probably pick out the beginners pretty well too. After that, fists start to fly :)