Nabble www.nabble.com

Really nice embeddable forum, hosted by nabble so no hassles.Customisable GUI lets the admin integrate it fully into the containing webbsite. Its a great service & free too

Nabble is a newcomer to the forum world. The UI is clean - as clean as the vBulletin's archive UI, but with rich features. It allows users to rate a post, through the collaborative rating. Users can work together to promote quality posts, and to kill spams and flame wars. Also, it has a great search function. vBulletin's search is weak compared with Nabble. Seasoned forum owners should take a good look at Nabble - when your forums grow big, inevitably they will get spammed, run into user conflicts (flame wars), or have too much content to search. Plus, it's truly free: no fees, no forced ads, no strings whatsoever.