Apple Wireless Keyboard the initial release. The new model now uses only two AA batteries instead of three originally. Additionally, Mac OS X 10.5.8 is now the minimum OS over the original Mac OS X 10.4.10. This model of keyboard became standard with new generation of iMacs introduced on the same day. On July 20, 2011, following the release of Mac OS X 10.7/OS X Lion, Apple updated the keyboard slightly, updating the label on the Exposé key to Mission Control and changing the Dashboard key to a Launchpad key. Keyboard layouts with a rectangular Enter key are available in American English and
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