Not sure but it appears to be the same as they use here: http://community.callofduty.com pretty versatile script even if its badly coded.
Hey I saw this post unanswered and if you are still looking for the answer, here it is: My best guess is that they are using Jive Software. http://www.cmswire.com/cms/enterpri...ging-im-and-support-for-opensocial-007775.php Cheers.