I've gotten the names servers routed to the three domains I wrote about earlier, and have different kinds of wiki software installed on each. Two programs -- TikiWiki and PhpWiki -- don't impress me and I've removed their databases. I'd remove them all, but don't want to leave empty holes.
The third site -- www.universalistpartnership.org -- has MediaWiki installed. This is what powers Wikipedia: serious software, but it wasn't any harder to set up than WordPress.
I'll try the MoinMoin wiki on one of the other domains, and perhaps Moodle (a distance learning application) for the third.
These are tire-kicking exercises, not for real action yet.