According to their web site:
Integration with 3rd party applications
Share the user database with the following 3rd party forum applications: vBulletin 2.2/2.3/3.0/3.5/3.6/3.7, UBB.threads 7.0/7.1/7.2/7.3 , phpBB 3.0, IP.Board 2.x, MyBB 1.2/1.4, and Simple Machines Forum (SMF) 1.1/2.0. No need to register twice. Additionally, it is possible to use forum threads for comments.
Is anyone here using this CMS, and if so, how do you like it? Pros & Cons