Vanilla Forum
I’ve had a notional wish list for forum software for ages. Right at the top of that list is “organise using categories rather than separate forums”. Just as I was about to get off my arse and do something about it (well, nearly) I stumbled across Vanilla. It does that and has a bunch of other features I like too. Lots of nice little AJAX (urk) touches in there as well.
If you’d like to come and play I’ve set up a Hexten forum here. I haven’t done much to customise it yet. Apart from turning on a few extensions that’s how it comes out of the box.

January 20th, 2006 at 12:30 am
We had that in phpwsBB at one point (end of 2003ish) but it gravitated towards cloning phpBB style forums as new developers piled in and I no longer had a need for developing a forum (ahem). There’s still vestigial category support in it so that a blog post or photo shows related forums alongside it but no longer at the post level. That was quite database hungry anyway.
One day I’ll strip out the phpBB shit and ban any developer from cvs who tries to implement a phpBB clone and put something like it back in.
I like the tabbed interface at the top though. I might nick that idea for the database pager class so I can use it on any list of categorised stuff.