What is the the engine (template) for the http://www.sitepoint.com/forums?

Hi,

What is the the engine (template) for the http://www.sitepoint.com/forums? And for this: http://www.qtcentre.org/forum/

This sites are very similar:

Where can I read about them? Are they free?

Thank you.

They are both vBulletin forums.

Thank you very much :slight_smile: