I hate phpBB. Its thread model encourages the wrong behaviour, its user documentation is so useless that the kludge of forcing designated threads to always appear at the top of the thread view to contain local rules has become standard practice, it enforces its own bizarro brand of almost-html, it doesn't support offline readers, and its terminology has replaced the perfectly good terminology we already had ("forum" for "BBS", "post" for "thread", etc.). Seems like a real step backward in forum technology.