ATOK is a Japanese input method editor (IME) developed by JustSystems. It allows users to type in Japanese using a standard keyboard by converting phonetic input into kanji, hiragana, or katakana characters. ATOK is known for its advanced predictive text features and user-friendly interface, making it popular among Japanese speakers. First released in 1987, ATOK has evolved over the years to support various platforms, including Windows, macOS, and mobile devices. It offers features like customizable dictionaries and cloud synchronization, enhancing the typing experience for both casual users and professionals.