Early versions of Windows handled both the differences between the two keyboards and the differences between American English and British English by having two English language options — a UK setting and a US setting. While adequate for users in the United States, United Kingdom, and Ireland, this solution caused difficulty in other English-speaking countries. In many Commonwealth countries and other English-speaking jurisdictions, local spelling conformed more closely to British English usage, while the supplied keyboard was printed with the United States layout on the keys. People in these countries were forced to choose between a keyboard layout incompatible with their hardware, or having their spell checker software flag the British English spelling of words such as "colour", "centre", etc. However, in more recent editions, the number of options was increased, allowing users to select the correct keyboard and dialect independently. For example, one is given a number of default options for locality that will usually correctly match dialect and keyboard. Further, even if the hardware keyboard layout does not match the device driver software layout that was pre-selected, it can be changed without changing the regional setting.
Since the standard US keyboard layout in Microsoft Windows offers no way of inputting any sort of diacritic or accent, this makes it unsuitable for all but a handful of languages unless the US International layout is used. The US International layout changes the `, ~, ^, ", and ' keys into dead keys for producing accented characters. The US International layout also uses the right alt as a modifier to enter special characters. The equivalent mapping for UK/Irish keyboards is called the "UK Extended" layout which, if activated in settings, will allow the user to enter a wide variety of diacritics which are not accommodated by the standard UK/Irish layout. In particular, à,è,ì,ò,ù used in Scots Gaelic can be made, the ŵ and ŷ used in Welsh. Likewise, the Spanish and Portuguese letters ñ and õ can be made. For more specialized uses, there is a facility in Windows for users to create a customized layout that may match their needs more precisely.
The non-standard default U.S. layout on Apple Macintosh computers allows input of diacritical characters, whereby the entire MacRomancharacter set is directly available. Apple supplies a "British" keyboard layout with the following differences:
The # symbol is replaced by the £ symbol ; the # is available by pressing +
More recent Apple British keyboards move the backquote/~ key to the left of the Z key and replace it with a section sign and a plus-minus sign, respectively.
The Enter key spans two rows and is shaped similarly to the Enter key of many ISO PC keyboards.
The " and @ keys are swapped.
Other keyboard layouts
Other operating systems can optionally re-map the keyboard layout or have different modifier keys. Under Unix/Linux the "Windows" key is often called the "Super" key and can be re-mapped by users for specific functionality but in most programs by default does nothing. Some older Unix/Linux software, such as Emacs, uses the left Alt key as a "Meta" key, which harks back to older MIT or LISP computers.
