Grey's Anatomy is an American medical drama television series that premiered on March 27, 2005, on American Broadcasting Company (ABC) as a mid-season replacement. The fictional series focuses on the lives of surgical interns, residents, and attending physicians, as they develop into seasoned doctors while trying to maintain personal lives and relationships. The title is a play on Gray's Anatomy, a classic human anatomy textbook first published in 1858 in London and written by Henry Gray. Shonda Rhimes developed the pilot and continues to write for the series; she is also one of the executive producers, along with Betsy Beers, Mark Gordon, Krista Vernoff, Rob Corn, Mark Wilding, and Allan Heinberg. Although the series is set in Seattle (at the fictional Seattle Grace, later known as the Grey-Sloan Memorial Hospital), it is filmed primarily in Los Angeles, California.