Showtime's expansion to national distribution in 1978 positioned the cable channel as direct competitor to Home Box Office, and the rivalry between the Showtime and HBO would continue for decades to come, through the era of theatrical-movie-based pay TV and into the age of internet distribution and original programming.
Through the 1980s, Showtime, like HBO, was a premium pay-TV service that aired mostly recently released, unedited theatrical movies. Also like HBO, Showtime supplemented its movie programming with special events such as concerts and sporting events.
With the rise in popularity of original cable programming in the 90s and 2000s, Showtime began producing more original dramatic series, focusing, again like HBO, on gritty, adult-oriented fare that took advantage of the pay channel's historical reputation. The violent thriller "Dexter" featured a serial killer as its protagonist, and "Californication" featured "X-Files" star David Duchovny as an author who struggles to overcome his addiction to sex. Other popular Showtime originals include "Weeds," featuring Mary Louis Parker as a suburban mom who becomes a drug dealer; "The Tudors," an action soap set in sixteenth-century England; and political thriller "Homeland."
Showtime is currently a subsidiary of CBS, and its network includes The Movie Channel and Flix.