We needed a forum for one of our web projects written in rails and a quick google revealed Savage Beast. It seemed to fit the bill although needed some css tweeks to co-exist with what we currently have. However, when clicking on its RSS feed icon it threw an ActionController::Request.relative_url_root method missing error which was fixed by creating the class request_error.rb in initializers with the code below:
@@relative_url_root ||= case
when server_software == ‘apache’
Based on bug reported here: http://railsforum.com/viewtopic.php?pid=73991#p73991.
It all seems to work fine now.