Westworld first came to the world in 1973 in the form of a motion picture written and directed by famed novelist Michael Crichton. The movie, which told the tale of a futuristic amusement park populated by robots gone haywire in the planet Delos (sounds familiar?) , gained enough success to spawn a sequel in 1976 ("Futureworld", in which Delos re-opens with a brand new theme park) and a 6-episode TV series called "Beyond Westworld".
The original Westworld remains to this day a Sci-fi classic, and was actually a pretty successful movie in it's day grossing a considerable amount for a SF flick done on a meager $1.25 budget and which featured one of the first computer-generated visual effects on a motion picture (the robot's distorted point of view shots).
As a side note, the "worlds" in the Delos from the movie are, besides Westworld itself, Romanworld and Medievalworld. Unlike the game's Samuraiworld and Orbitworld.
Trivia contributed by Zovni.