ATOK

ATOK (エイトック /ˈetoku/ or /ˈeɪtɔːk/) is a Japanese input method editor (IME) produced by JustSystems, a Japanese software company.
ATOK is an IME with roots from KTIS (Kana-Kanji Transfer Input System) come with JS-WORD, the Japanese word processor software for PC-100 in 1983, but it now supports a variety of platforms including macOS, Windows, Android, and iOS.
Once ATOK meant" Automatic Transfer Of Kana-kanji". Now, it means " Advanced Technology Of Kana-kanji Transfer". It is occasionally taken to stand for Awa-TOKushima", site of the headquarters of JustSystems, or Alphabet TO Kanji."
Functions.
Functions vary between versions for different platforms, and the following list is not exhaustive.
Versions.
As of April 2019, the latest version for Windows is 31.1.6; for macOS, 31.0.3; for iOS, 1.6.2; and for Android, 1.8.15. They are available via the ATOK Passport subscription and an annual subscription which comes with Ichitaro. Linux, OS/2, Palm OS, Pocket PC, and Windows CE are no longer supported.
KTIS and ATOK was originally a component of JustSystems' word processor software. Ichitaro released in 1985 allowed the use of ATOK 4 in other MS-DOS applications of the PC-98 platform. ATOK 7 was bundled with Ichitaro 4, and was available as a standalone product in 1992. In DOS era, ATOK was spreading with Ichitaro despite competition from VJE, Matsutake, and some other softwares. Windows 3.1, the first retail version of Japanese Windows, bundled the Microsoft IME (MS-IME) input method. MS-IME 97 contained notable improvements, and was bundled with a new retail box of Windows 95 and Office 97. The difference between ATOK and MS-IME went smaller.
In 2008, JustSystems began a subscription service, ATOK Passport. ATOK 2017 was the last version to be physically shipped as boxed software.
Sun Microsystems chose ATOK as their input method when running under the JP locale in Solaris 10 and above, enhancing Sun's already strong Japanese language support.
For embedded systems, JustSystems has developed +ATOK. Some Japanese mobile phones, PDAs, video game consoles (PSP, PS3 and Wii), digital video recorders, automotive navigation systems come with +ATOK.