I always intended to revive the message forum after I switched the website from Postnuke to MoveableType. I decided to go with phpBB for several reasons. First, the person who wrote it is a reader of Ars Technica and its OpenForum, which I help moderate. phpBB also uses Smarty, a really cool php templating system. All in all it makes for a nice, solid system. I’ve done a little customization to try to match the theme of the forum with the main site.