Just so nobody thinks that Zope is perfect for everyone, here is an article I came across that goes the other way, Why We Don't Use Zope. Not sure I agree... but it is good debate material.

"The ultimate lesson is that features exact a cost whether you end up using them or not. For example, Zope's through-the-web editing means code has to live in an object database, and a complicated security model is therefore required to control access to the code. Object traversal is complicated because objects can affect how they're traversed. DTML is handy for simple tasks, but complicated applications become really messy because it provides few tools for cleanly structuring a subsystem."