Mojikyō

Mojikyō (Japanese: 文字鏡), also known by its full name Konjaku Mojikyō (今昔文字鏡, lit. '(the) past and present character mirror'), is a character encoding scheme created to provide a complete index of characters used in the Chinese, Japanese, Korean, Vietnamese Chữ Nôm and other historical Chinese logographic writing systems. The Mojikyō Institute (文字鏡研究会, Mojikyō Kenkyūkai), which published the character set, also published computer software and TrueType computer fonts to accompany it. The Mojikyō Institute, chaired by Tadahisa Ishikawa (石川忠久), originally had its character set and related software and data redistributed on CD-ROMs sold in Kinokuniya stores.

Conceptualized in 1996, the first version of the CD-ROM was released in July 1997. For a time, the Mojikyō Institute also offered a web subscription, termed "Mojikyō WEB" (文字鏡WEB), which had more up-to-date characters.

As of September 2006, Mojikyō encoded 174,975 characters. Among those, 150,366 characters (≈86%) then belonged to the extended Chinese–Japanese–Korean–Vietnamese (CJKV) family. Many of Mojikyō's characters are considered obsolete or obscure, and are not encoded by any other character set, including the most widely used international text encoding standard, Unicode.

Originally a paid proprietary software product, as of 2015, the Mojikyō Institute began to upload its latest releases to Internet Archive as freeware, as a memorial to honor one of its developers, Tokio Furuya (古家時雄), who died that year. On 15 December 2018, version 4.0 was released. The next day, Ishikawa announced that without Furuya this would be the final release of Mojikyō.