Sunwoo Entertainment, Co., Ltd. is an animation studio located in Seoul, South Korea. It was established as Sunwoo Production Inc. in 1974. They started doing animation in 1979 (though they existed as a company as early as March 1974), first working on South Korean productions, then for Disney nearly a decade later and have since become one of the busiest overseas animation studios.
It began by producing animation mainly for Disney Afternoon TV series, such as Chip 'n Dale Rescue Rangers and Darkwing Duck, and soon expanded by providing animation services for Nickelodeon shows like Rocko's Modern Life and Invader Zim, and other series like Duckman on USA Network and Fatherhood on Nick at Nite.
Many studios have been "spun off" from Sunwoo; the first to do so was Anivision, which was established in March 1991. Anivision worked on The Simpsons, with AKOM and Rough Draft Studios, and Rugrats, replacing Wang Film Productions for its 2nd season in 1992.
Grimsaem Animation Co. Ltd., Seoul, Korea, which mainly does feature-length work for Nickelodeon, was established in March 1997. In April 1998, Sunwoo Digital International was established, whose most notable work was for the Fox TV series Family Guy.
In April 2000, all of these spin-off studios were merged under the banner Sunwoo Entertainment, and it has remained that way ever since.
According to wikipedia