David Michael Letterman is an American former television host, comedian, writer, and producer
He hosted a late night television talk show for 33 years, beginning with the February 1, 1982 debut of Late Night with David Letterman on NBC, and ending with the May 20, 2015 broadcast of Late Show with David Letterman on CBS. In total, Letterman hosted 6,028 episodes of Late Night and Late Show, surpassing friend and mentor Johnny Carson as the longest-serving late night talk show host in American television history. In 1996 Letterman was ranked 45th on TV Guides 50 Greatest TV Stars of All Time.
Letterman is also a television and film producer. His company, Worldwide Pants, produced his show as well as The Late Late Show with Craig Ferguson and several prime-time comedies, the most successful of which was Everybody Loves Raymond, currently in syndication.
Several late-night hosts have cited Lettermans influence, including Conan OBrien (his successor on Late Night), Stephen Colbert (his successor on The Late Show), Jimmy Fallon, Jimmy Kimmel and Seth Meyers.
Source: Wikipedia