It's funny that they mention BeOS because I think it had a nice solution to keyboard app switching: Alt-tab switched programs (it had the same Mac-like app-cen

It's funny that they mention BeOS because I think it had a nice solution to keyboard app switching: Alt-tab switched programs (it had the same Mac-like app-centric design), and it looked somewhat like the traditional Windows. With Alt still pressed, you could use the up/down arrow keys to move within windows for that app. I wish I could find a screenshot of it.