A popular korean MMORPG game, published by NEXON. It was licensed by KRU Interactive and localized as Nexus: The Kingdom of the Winds.
The source code was based on a MULTI-USER DUNGEON created by Jake Song which was written in the Objective-C programming language. Jake Song created the MUD during his studies at KAIST (Korea Advanced Institute of Science & Technology) in 1994.
Although over a decade old now, it is still one of NEXON's most popular products. It has enjoyed considerably greater success than any of its localizations has.