Just a question I'd like to throw out to the geekhack massive, why do different countries use different keyboard layouts?
Well, there are several different answers to this question, depending on which question you're asking.
Japan and Korea use special keyboard layouts, because their keyboards need extra keys to allow convenient switching of modes for the Input Method Editors (IMEs) used for their languages.
Germany uses QZERTY... and France uses AZERTY... because these were traditional arrangements of keys for typewriters in their countries. (Belgium and Portugal also used unusual keyboard arrangements, but these haven't survived into the computer age.) Obviously, too, depending on what language you're using, you will need the appropriate accented letters. Even in Britain, there's a difference - you need the British pound sign on your keyboard, just as much as people need dollar signs in the U.S..
As for ANSI versus ISO: ISO is an international standard, which is why it is used for keyboards in many countries. As well, it offers an extra key on the keyboard, allowing people to use more characters directly when typing.
Why doesn't the U.S. also use the ISO layout?
The ISO layout places a key between the letter Z and the left-hand shift key. Also, it places three keys, instead of two, between the letter L and the Enter key. This means that the ISO layout, unlike the ANSI layout, puts these very important keys in different, harder-to-reach, positions than the left-hand shift key and the carriage return key had on electric typewriters.
The original IBM PC keyboard was similar to the ISO keyboard in these respects, and there was a great deal of annoyance on the part of typists in offices that were using the IBM PC. This eventually led to the keyboard of the IBM Personal Computer AT resolving those issues - but now the
backspace key was moved one position further to the right.
The ANSI layout of the Model M keyboard finally resolved all the issues, providing a design that largely matched a typewriter keyboard.
Since typewriter keyboards in Europe, as well, originally didn't have as many keys as computer keyboards do now, it does perplex me that, even if an extra key is needed in European countries, that some other way of accommodating it, resulting in a keyboard more closely resembling the ANSI layout, had not been used.
Why the ANSI keyboard standardization effort went the way it did, however, is a question for which I don't have an answer.
Here, though, is the perfection - even beyond that of the Model M - despite making room for both the extra international key, and two Windows shift keys, and the Windows menu key - that I wish the world would all agree on:
Some of the rationale of this design is explained more fully at the bottom of
this page on my web site. Note that I use the convention of marking the Windows keys with a diamond rather than raising any issues by using a trademark in my illustrations.