If you've used both Emacs and Microsoft's new ribbon interface which can be found in Microsoft Office 2007 onwards you'll probably be able to relate to what I'm saying.
Emacs is known for it's multi-key shortcuts: Ctrl-X, Ctrl-C to exit, Ctrl-X, Ctrl-F to open, etc..
Let's take Paint in Windows 7 for example, to save as you press Alt, F, A (Alt shows the shortcuts, F opens the file menu, and A is for the Save As menu item), Alt, H, RP to crop the image (Alt shows the shortcuts, H opens the home tab, RP is the shortcut for Crop).
However, the way they implemented it is a lot more intuitive than Emacs's; you can learn them in no time, you just press Alt and all the shortcuts appear in front of you, not only that, having the shortcuts organized by menus and tabs makes it a lot easier to get used to the shortcuts; you press the shortcuts for the menu and then the shortcut for the item in it.
All this supports what I said previously about open source's initiatives.