If you want to kick start it all please take a look at http://svn.ecclestoad.co.uk/svn/forum/trunk/. It is at the moment a fairly basic forum but it has some nice touches like policies and so on. It is still in development so there is plenty of work to do : )
It is based on Catalyst and does the database side using Class::DBI::DFV (which got pushed to CPAN yesterday). It currently requires a PostgreSQL database, but that should be quite easy to set up. I need to write a guide to installing it - I'll do that in the next few days. The templating is done using HTML::Mason and it is fully internationalised. When it is ready I was going to put it on CPAN.
If you're interested let me know.