bbPress is the forum plugin for WordPress designed “the WordPress way’. What it means is: bbPress easily integrates with WordPress, installs in a few clicks and has an extremely intuitive user interface. Add also lightweight and speed, and this makes a great addition.
More than that, bbPress can be used even with WordPress multisite and be extended thanks to a number of plugins. Being open-source and free, bbPress allows to modify the forum according to your wishes both in appearance and functions.
Switch to bbPress with CMS2CMS - and you won’t believe that a migration can actually be a breeze and for reasonable price!