Comment 39 for bug 91784

So the best way of making the current functionality understandable is to fix the showdesktop bugs and tweak it a bit. Basically instead of showdesktop moving windows it should shape their input away, move their _textures_ to the sides of the screen, draw a black bar around the edge of the screen, and make it so when you click on the edge you exit show desktop mode. Also, opening new windows should not exit show desktop mode but trying to show a current hidden window should.

Yes, I realize this is exactly how OS X does it but that's sort of the point; we like that method of doing it but never quite got there.