Command key keyboard of the NeXT Computer that key was marked in green. The menus were not marked with a symbol denoting the command key. Besides being used as a modifier key for keyboard shortcuts it was also used to alter the function of some keys. toggles alpha lock, sends Enter and toggles Mute. The functions were printed in green on the front side of the modified keys. This was also done on the Z, X, C and V keys (Undo, Cut, Copy and Paste). On the NeXT ADB keyboard, the Command keys were replaced by keys labeled and the Command key
QWERTY studies administered by Dvorak himself before and after World War II. Economists Stan Liebowitz and Stephen Margolis have noted that rigorous studies are inconclusive as to whether they actually offer any real benefits, and some studies on keyboard layout have suggested that, for a skilled typist, layout is largely irrelevant – even randomized and alphabetical keyboards allow for similar typing speeds to QWERTY and Dvorak keyboards, and that switching costs always outweigh the benefits of further training on whichever keyboard you already use. The most widely used such alternative is the Dvorak Simplified Keyboard; another alternative is Colemak, which is