I did not know that yesterday!

The QWERTY is the most common modern-day layout of letters on most English language computer and typewriter keyboards. It takes its name from the first six letters shown on the keyboard's top row of letters. The QWERTY design was patented by Christopher Sholes in 1868 and sold to Remington in 1873, when it first appeared in typewriters.

Purpose
Frequently-used pairs of letters were separated in an attempt to stop the typebars from intertwining and becoming stuck, thus forcing the typist to manually unstick the typebars and also frequently blotting the document. The home row (ASDFGHJKL) of the QWERTY layout is thought to be a remnant of the old alphabetical layout that QWERTY replaced. QWERTY also attempted to alternate keys between hands, allowing one hand to move into position while the other hand strikes a key. This sped up both the original double-handed hunt-and-peck technique and the later touch typing technique; however, single-handed words such as stewardesses and monopoly show flaws in the alternation.

It has often been noted that the word typewriter can be typed entirely using the top row of the QWERTY keyboard: it has been speculated that this may have been a factor in the choice of keys for ease of demonstration.


Languages other than English
This French Matra Alice uses the AZERTY layoutMinor changes to the arrangement are made for other languages; for example, German keyboards add umlauts to the right of "P" and "L", and interchange the "Z" and "Y" keys both because "Z" is a much more common letter than "Y" in German (the latter appearing seldom except in borrowed words), and because Z and A often appear next to each other in the German language; consequently, they are known as QWERTZ keyboards. French keyboards interchange both "Q" and "W" with "A" and "Z", and move "M" to the right of "L"; they are known as AZERTY keyboards. Italian typewriter keyboards (but not most computer keyboards) use a QZERTY layout where "Z" is swapped with "W" and "M" is at the right of "L". Portuguese keyboards maintain the QWERTY layout but add an extra key: the letter C with cedilla (Ç) after the L key. In this place, the Spanish version has the letter N with tilde (Ñ) and the Ç (which is not used in Spanish, but is part of sibling languages like French, Portuguese and Catalan) is placed at the rightmost position of the home line, beyond the diacritic dead keys. Other languages that use the Latin alphabet have other small variations on QWERTY.


Alternative keyboard layouts
Because modern keyboards do not suffer from the problems of older mechanical keyboards, the QWERTY layout's separation of frequently used letter pairs is no longer strictly necessary. Several alternative keyboard layouts, such as Dvorak Simplified Keyboard arrangement (designed by Drs. August Dvorak and William Dealey and patented in 1936), have been designed to increase a typist's speed and comfort,
largely by moving the most common letters to the home row and maximizing hand alternation. The effectiveness of these layouts is disputed, but it is often claimed that world records for typing speed are usually set on Dvorak layout keyboards. Some studies have shown that alternative methods are more efficient, but Dvorak and other alternative typists most often cite comfort as the greatest advantage. QWERTY's inventor, Christopher Sholes himself patented a key arrangement similar to Dvorak's, but it never became popular.

Some researchers claim that QWERTY is really no less efficient than other layouts, such as economists Stan Liebowitz at the University of Texas at Dallas, Texas, and Stephen E. Margolis of North Carolina State University. Other opponents claim that August Dvorak stood to gain from the success of his layout, and that he perpetuated his "efficiency myth" to increase his financial gains. Other QWERTY advocates claim that for a QWERTY typist to switch to Dvorak or another layout requires more effort than initially learning to touch-type, because of having to retrain the fingers' muscle memory. Computer users also need to unlearn the habit of pressing key-shortcuts (for example: ctrl-c for copy, ctrl-x for cut), though some programs and operating systems allow the use of alternate layouts combined with QWERTY shortcuts.

However, opponents of alternative keyboard designs most often point to QWERTY's ubiquity as a deciding factor, because the costs incurred by using the supposedly inefficient layout are much less than those of retraining typists. In fact, the Dvorak layout is sometimes used as an example in businesses to illustrate the difficulty of change. It is not unusual to find Dvorak typists who also touch type the QWERTY layout, for convenience owing to QWERTY's ubiquity.

The XPeRT Keyboard alternative was designed to try to overcome the problem of resistance to change, by minimizing change from Qwerty. It moves only two common letters, A+N, and adds a second E key (13% of all letters); Dvorak moves 24 letters. Dvorak has five frequently used letters at outer finger locations (A,S,O,R,N); XPeRT has only one (S) and others are central. XPeRT increases opposing hand key sequences
(digraphs) from 50% on Qwerty, to 83% on XPeRT, to increase typing speed. Dvorak was designed this way too, and scores 80% for opposing hand digraphs. The Dvorak keyboard focusses on the home row, reducing finger reach and travel; the XPeRT keyboard does not take this approach, choosing to minimize change from Qwerty instead. Digraph statistics listed here are derived from the Dvorak keyboard US patent of 1936.


Trivia
The word QWERTY was the first message ever sent by e-mail. The longest common English word that can be typed using only the left hand (using conventional hand placement) is stewardesses. The words sweaterdresses and aftercataracts are longer and can also be typed with only the left hand, but they are not in all dictionaries.
The longest English word that can be typed with the right hand only (using conventional hand placement) is johnny-jump-up, or alternatively polyphony. Typewriter is not the longest word that can be typed on only one row, as is sometimes conjectured. Proprietory, protereotype and rupturewort, eleven and twelve letter words, can all be typed only with keys found in the top row.