I've been playing around with different kinds of wiki's for documenting Neubia. So far my favorite is Russel Beattie's SimpleWeb.
There is no documentation, but it's quite easy to configure. Most things are in web/WEB-INF/global.jspf if you're in doubt.
I haven't customised it much yet, but will do so eventually.
You can see what I've got so far at Neubia Wiki. Currently it's running on a built in hSQL database, but I will move it to mysql or postgresql before I get too far.
Just saw from Russel's WebLog that he's thinking about adding Simple web logging capabilities as well. Which is cool. Keep up the good work.