Editing Compose key (section)

==Software support==

===X Window System===
X header files call the Compose Key the "Multi_key". On [[Xorg]] the default Compose Key is {{key press|Shift}}+{{key press|AltGr}},<ref>{{cite web|title=Compose Key|url=https://help.ubuntu.com/community/ComposeKey|publisher=Ubuntu|access-date=2012-07-10}}</ref> (while pressing {{key press|AltGr}} ''before'' {{key press|Shift}} is the "fourth keyboard level modifier", a different key). On [[Gentoo Linux]] the Compose Key is disabled by default.<ref>{{Cite web |title=Compose key - Gentoo wiki |url=https://wiki.gentoo.org/wiki/Compose_key |access-date=2024-04-27 |website=wiki.gentoo.org}}</ref> As this is rather inconvenient (especially for keyboards without an {{key press|AltGr}}), it is common to select a keyboard layout where another key such as the right-hand {{key press|Ctrl}} or {{Key press|[[Windows key|Win]]}} is mapped to the compose key. This option is normally available in the settings of the desktop environment. The X keyboard driver does not allow the key used for Compose to also function as a modifier.{{Citation needed|date = July 2015}} On modern systems a vast number of compose sequences are supported.<ref name=xorg>{{cite web |url=http://cgit.freedesktop.org/xorg/lib/libX11/plain/nls/en_US.UTF-8/Compose.pre |title=UTF-8 (Unicode) compose sequence |last=Monniaux |first=David |access-date=2015-07-15}}</ref>

===Windows===
On Microsoft Windows, a few programs such as [[PuTTY]] provide compose-key support.{{citation-needed|date=May 2023}} To emulate the compose key for all software, keyboard shortcut utilities are often involved. There are also a number of [[open-source license|open-source]] [[Utility software|utilities]] (such as WinCompose,<ref>[https://github.com/SamHocevar/wincompose Compose Key for Windows] – GitHub.</ref> AllChars,<ref>[http://sourceforge.net/projects/allchars/ AllChars] – SourceForge.net.</ref> Compose-Keys,<ref>[https://github.com/MrBertie/compose-keys Compose Keys] – GitHub.</ref> or Compose<ref>[https://github.com/p3lim/Compose Compose] – GitHub.</ref>). Installable keyboard layouts (such as KbdEdit<ref>[http://www.kbdedit.com/manual/ex17_compose_key_chained_dead.html KbdEdit – Emulating Compose key using chained dead keys].</ref>) are available that contain a compose key assigned to one of the keys like {{key press|Ctrl}} or {{key press|AltGr}}. They work by using the [[dead key#chained dead keys|dead-key chaining]] feature that is more commonly used to input letters with multiple diacritics. Such keyboard layouts can also be programmed directly in C (the language Windows drivers are written in), compiled using the free-of-charge Windows Driver Kit,<ref>[https://www.microsoft.com/en-us/download/details.aspx?id=11800 Windows Driver Kit Version 7.1.0] – Official Microsoft Download Center.</ref> and packaged using the free-of-charge Microsoft Keyboard Layout Creator 1.4,<ref>[https://www.microsoft.com/en-us/download/details.aspx?id=102134 Microsoft Keyboard Layout Creator 1.4] – Official Microsoft Download Center.</ref> compatible up to the latest versions of the OS.

===macOS===
Although the [[Cocoa (API)|Cocoa]] text input system allows entry of many alternate and accented characters natively in macOS,<ref name="uscustom">{{cite web |url=http://uscustom.sourceforge.net/ |title=U.S. custom Keyboard Layout |last=Wust |first=J. 'Mach' |website=SourceForge |date=2015-06-29 |access-date=2015-07-07}}</ref> a true compose-key solution is not built in. At least one has been implemented using the Karabiner utility,<ref name="Lol Engine" /> which works with all applications, as does the use of certain keyboard layouts (e.g. "ABC – Extended") where Compose is implemented using the dead key chaining feature.<ref name="uscustom" />

===ChromeOS===
Although [[ChromeOS]] is [[QWERTY#Chrome OS|supplied with]] a larger repertoire of glyphs than most competitors, the chords needed to achieve them are not always as obvious as the Compose concept provides. Google has made available an add-on (ComposeKey) to compete in this market.<ref>{{cite web|url= https://github.com/google/extra-keyboards-for-chrome-os/tree/master/composekey | title= extra-keyboards-for-chrome-os/composekey/ | website=github.com | access-date=28 January 2020}}</ref><ref>{{cite web | url=https://chrome.google.com/webstore/detail/composekey/iijdllfdmhbmlmnbcohgbfagfibpbgba |title = ComposeKey| website=Chrome Store  | access-date=28 January 2020}}</ref>

===DOS===
Under DOS, compose key support depended on the running application, or on a loadable keyboard driver. For example, [[Lotus 1-2-3]] used {{keypress|Alt|F1}} as compose key to allow easier input of many special characters of the [[Lotus International Character Set]] (LICS)<ref name="HP_1991_95LXUG">{{cite book |title=HP 95LX User's Guide |publisher=[[Hewlett-Packard Company]], Corvallis Division |location=Corvallis, OR, USA |edition=2 |chapter=Appendix F |date=June 1991 |orig-year=March 1991 |id=F0001-90003 |url=http://www.retroisle.com/others/hp95lx/OriginalDocs/95LX_UsersGuide_F1000-90001_826pages_Jun91.pdf |access-date=2016-11-27 |url-status=live |archive-url=https://web.archive.org/web/20161128202642/http://www.retroisle.com/others/hp95lx/OriginalDocs/95LX_UsersGuide_F1000-90001_826pages_Jun91.pdf |archive-date=2016-11-28}}</ref> and [[Lotus Multi-Byte Character Set]] (LMBCS).