Wikipedia
McCune–Reischauer romanization is one of the two most widely used Korean language romanization systems, along with the Revised Romanization of Korean, that replaced (a modified) McCune–Reischauer as the official romanization system in South Korea in 2000. A variant of McCune–Reischauer is used as the official system in North Korea.
The system was created in 1937 by George M. McCune and Edwin O. Reischauer. With a few exceptions, it attempts not to transliterate Korean hangul but to represent the phonetic pronunciation. McCune–Reischauer is widely used outside Korea. A variant of it was used as the official romanization system in South Korea from 1984 to 2000. A third system, the Yale Romanization system, which is a transliteration system, exists but is used only in academic literature, especially in linguistics. During the period of Russian interest in Korea at the beginning of the 20th century, attempts were also made at representing Korean in the Cyrillic alphabet by the Kontsevich system.