The TNG integration isn't a full implementation, which doesn't exist as far as I am aware, at least not for recent versions of TNG and Joomla!. It does use the TNG-Joomla Bridge component by Cas Nuy, Mark Fleeson, Joe Cox and others, in conjunction with the Joe Cox unwrap hack to show TNG unwrapped in Joomla, with SEF URLs.

If you have a TNG site and you're interested in doing the same, feel free to contact me for more information.