ergophobe - 3:47 pm on May 8, 2012 (gmt 0)

Wow... you say "the Drupal framework" which tells me you're thinking about Drupal the right way - the power is in the framework, not that app and Drupal has more and more JQuery integration, more and more AJAX. That said, I haven't seen anything that asynchronous in any CMS.

That said, they all have fully customizable front ends, but I don't know of any off-the-shelf themes that are that AJAX-heavy.