In OSX Snow Leopard, one can push all of the open windows to the side of the screen (revealing the desktop) by pressing F11. Further, by pressing F11 again, all of the windows are returned to their original state. My question is: Does OSX Mavericks have an equivalent shortcut and if so, what is it? (Note that this Snow Leopard shortcut is not enabled by default on portable Macs).
First, the keyboard shortcut in 10.6 Snow Leopard (and almost all versions of OS X) for Expose "Show Desktop" is not F11 unless you have 'Use all F1, F2, etc. keys as standard function keys' clicked in System Preferences > Keyboard.
It's actually, by default fn-F11. Exactly the same as it is in 10.9 Mavericks. I suspect that under 10.6 you had the System reversing the standard by clicking the above and got used to that and 10.9 is set to the default where F11 adjusts the volume. Try fn-F11 and it should work. Of course if you want it the other way round then change it in System Preferences.