A few of the head VB developers made a forum software called XenForo, just came out today I think
VB currently has them in a lawsuit though
News article about lawsuit- http://www.theregister.co.uk/2010/10/05/vbulletin_sues_ex_employees/
Anyways I've already been on a few sites using this software and it seems great, better than VB if you ask me. Anyways yeah I think it would be a good one to add to your list
Thanks for the information, XenForo is already on our TODO list. The buzz around this forum is quite amazing!
FSR Admin - Vote for 2012.
It's not a fork, and you're not doing anyone any favors by saying it is.
It's a new project started by ex-vBulletin developers.