Soul of the Ultimate Nation (often abbreviated as SUN ) was a fantasy-based massive multiplayer online role-playing game (MMORPG) produced by Webzen , a Korean-based company. It is operated in Korea by Webzine and Mainland China by The9 . The game was launched in Taiwan on April 19, and in China on May 24, 2007 as a paid online service  and closed on July 3, 2013.
In December 2005, Webzen sold an export contract for the game to The9 for $ 13 million USD in total, which was the largest single transaction in Korea’s online game history.  In 2006, SUN was selected as the most anticipated online game at the 2nd Annual Best Online Game Selection in China.  In a survey by Gametrics, the largest Internet cafe in Korea, SUN was ranked among the top 10 games in Korean Internet cafes.  Also, SUN received the award at the Digital Content Awards by Ministry of Information and Communication and SK Telecom  in 2006.