A Viacom company. Once a series has been succesful on HBO, it is sold to Showtime. The same holds for movies; Showtime has original porn. The Showtime package on the Dish Network consists of 8 Channels, including Sundance and TMC. HBO only has 6, two of which are duplicates.

Update: sfc says re showtime: This isn't true. Showtime has original shows, and I can't think of many that originated on HBO.