MyBestBB is a full-featured forum based on punBB.
It adds many features, modifications, and themes to the default punBB, including RSS feeds, UTF-8, XHTML 1.0 strict compliance, sub-forums, PMs, attachments, rewrite rules, the ability for an admin to move posts, easy smilies, easy polls, many improved themes, announcements and sticky topics, an activity barometer, a URL rewriting module, and much more.