Maxbrowser mode - where/how?

On the MultiZilla screenshots page 
(http://multizilla.mozdev.org/screenshots.html) there is a screenshot of 
"Maxbrowser" mode that looks like mozilla mail/news, browser, etc are 
all in one window in individual tabs.  I have looked all over, and can't 
seem to find any relevant settings.  Any hints on how to do this? is it 
possible even? Note that I do have the "Messenger" checkbox checked in 
the Preferences->MultiZilla->Links dialog.

Thanks for any tips/hints!
Nate