This looks darn handy. It's a Revit 2013 add-on utility that arranges your viewports in Revit. You may already now some of the keyboard shortcuts like WT for window tile, ZA for zoom all, and Ctrl-Tab for switching between open windows, but this utility gives you even more handy flexibility in arranging windows. It's called Palladio X and it's free, thanks to the folks at Mensch und Maschine Software SE. I like the classic architectural reference in the name.
Check it out here on the Autodesk App Exchange.
Left: Revit managed viewports - Right: Palladio X managed viewports
Nicely stacked viewports...
Now if you are working on a large project, keeping this many windows open may decrease your performance and may not be a good idea. It would be a good idea to close the ones not in use. That being said, there are lots of working scenarios where this utility would be very handy. If you try it out, leave a comment. Thanks to Markb for posting this to Revitforum.org