[Zope] Using GPL'd modules with Zope?

Hello, I am a bit confused on how to use GPL'd modules, like Xron, with the other non-copyleft licenses like BSD and ZPL. Do i have to make my whole Zope installation copyleft if I use a GPL'd module. Or, Is it just that single module that is copyleft and I can retain ownership of my own code? Thanks, Derek Basch __________________________________________________ Do you Yahoo!? Faith Hill - Exclusive Performances, Videos & More http://faith.yahoo.com