I have no idea why it has groups since you can't set permissions to articles/categories.


That is wrong. You can grant access to user-groups by categories, etc.

Yoothemes Zoo, I tried it quickly, but it seams not to work with another prefix than jos_ in the DB, thats a nice one.

@nick ; u sounds like a Yoo fan boy too. PM me a description how the Zoo works and to make a page, and I will talk about that