Finally got down to it and installed a wiki.
MoinMoin was easy to config on Gentoo but a pain for Fedora Core 1. MediaWiki, in contrast, was a breeze to install on both. It feels like a little overkill for my needs (way too much cruft for a personal “offboard brain” with only one user), but at least it’s there now. I’ll look into customization later.
The only bad part is that all the page data seems to reside in mysql. That means no filesystem access for easy hacking (script-generated pages, or pages that scripts can read). Disappointing, because I was looking to hacking something similar to the app described in this page: a unix calendar-like script that takes a wiki page as input.
Time, time, time…
Edit:
A year later, I find MoinMoin has matured a bit and is now easier to install. It’s a lot less of a Heavyweight Bruiser, much more suited to my needs.