When the curtain goes up on this cable broadcaster, it's really Showtime. Showtime Networks operates a portfolio of leading pay-TV channels including its flagship Showtime service, which offers movies, special events, and original series such as Dexter and Homeland. It also offers on-demand programming, and owns sister pay-TV services The Movie Channel (recently-released movies) and FLIX (movies from the past several decades). Altogether Showtime, The Movie Channel, and FLIX boast more than 67 million cable and satellite subscribers. Showtime Networks also owns a joint venture with the Smithsonian that operates the Smithsonian Channel. Part of media giant CBS Corp., Showtime first went on the air in 1976.