2
Covered briefly in this
FAQ...
I tried phpNuke first, and ditched it about an hour later. I can't remember why now, but it was the first CMS I looked at (and my boss was trying to make me use it for our Intranet). I just didn't like it - it seemed a bit too tricky to do certain things, and other things were just not possible.
So I read many 'CMS vs CMS' publications on the net, and suffice to say XOOPS came up trumps on most issues, most importnatly the fact that there's so many modules for it and the developers and community are massively helpful.
I gave it a whirl, and was up and running with a basic site very quickly. Obviously I had the usual difficulties that most people have in the first few months and got quite frustrated from time to time (and still do!), but eventually grasped it.
Xoops is complex but highly scalable and highly customisable. Thousands of themes, hundreds of modules. In my mind, it's got the most power of any CMS type system.