I was looking at this as a groupware solution and, of course, the 
description sounded a lot like PostNuke, but I was wondering if anyone 
had messed with it and could give me some feedback.

I would ideally like to find something that I can install and just use.  :-)

I installed PostNuke on the machine at home running YDL 3.0, but it is a 
bit slow and I'd like to see if Tiki works any better.

Ideally, what we would use would be a total groupware solution with 
calendar and all, with shared calendar in particular.

Thanks!

Chris