I use it on one of my websites. It's pretty stable, has polls, works with flat files, has an event calendar, Personal Messaging, forums, linksmanager, the whole lot.

Works with templates so every user can have his own gui, if you want. I'm using 0.6 version but the new 0.7 version is somewhat slicker with several add-on modules, which you as a perl monk can easily create yourself.

Worth checking out.