The onyl issue is that the list on that link is from 2005, SimpleMachines isn't even listed. I would say they are below vBulletin but above phpBB. Simplemachines.org
get a .asp forum or maybe .php i also heard .jsp are better http://www.mvnforum.com/mvnforumweb/index.jsp java ftw
There are many free and paid forums available. You can install as per your budget and requirement. You will get the installation guide with most of the forums. Kailash
If you have a control panel for your domain, almost all of them provide a free php forum along with it.
PHPBB is the best free forum. vBulletin is the best paid forum. The choice is yours. I run both and I have to say, vB is absolutely amazing! Well worth the money.
phpbb is the best forum if you can wirte program, you can develop your own interface and function on php3 vbulletin is the best paid forum, about $110 one year