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 1983 and DOS, but it now supports a large number of platforms including Linux, Mac OS X, Windows, Android, and iOS.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.