Alien (1979), directed by Ridley Scott, is an extremely popular and influential science fiction/horror film that spawned several sequels and imitators. more...
Although the title characters are the highly aggressive extraterrestrial creatures (Xenomorph is the proper name of this species), the real connecting thread is the saga of Ellen Ripley, played by Sigourney Weaver, a human woman who finds herself the principal opponent of the species throughout the series. The film is especially notable as the first major American film series with a female action hero.
There are just seven human actors in the movie: Tom Skerritt (Captain Dallas), Sigourney Weaver (Warrant Officer Ripley), Veronica Cartwright (Navigator Lambert), Harry Dean Stanton (Engineering Technician Brett), John Hurt (Executive Officer Kane), Ian Holm (Science Officer Ash), and Yaphet Kotto (Chief Engineer Parker).
The film's visual imagery was designed by H.R. Giger, for which he won an Oscar.
In 2002, the United States Library of Congress deemed Alien "culturally significant" and selected it for preservation in the National Film Registry.
The eponymous alien creature is a lethal predator with consistently exotic abilities and physical attributes, and which reproduces by parasitizing living victims. The plot device of the alien having acid for blood was created in order to prevent the Nostromo's crew from being able to kill it easily with firearms—the spilled blood would have eaten through the ship's hull. On the other hand, a flamethrower proved to be a suitable weapon, even though they have a limited firing range. The life cycle of the alien has been compared to that of the ichneumon wasp due to its parasitoid nature.
After the ship's Captain is captured by the alien in a botched attempt to trap the creature, Ripley assumes command. She discovers that the ship has been deliberately re-routed by the Company that owns it to investigate a non-human distress signal and to return a specimen. The Science Officer Ash is revealed as an android, placed by the Company on short notice at Thedus to protect the creature, with instructions to regard the crew as "expendable". Ripley — as the sole survivor of the Nostromo — initiates the ship's self-destruct sequence, escapes in a shuttle craft, and finally destroys the alien by blowing it out of the airlock into open space.
The original screenplay was written by Dan O'Bannon, who had collaborated with John Carpenter on the cult sci-fi film Dark Star. O'Bannon's original script was titled Star Beast, and was a revision of an idea O'Bannon had years before, about gremlins getting loose aboard a World War II bomber and wreaking havoc with the crew.
O'Bannon's original script bears many resemblances to the film that was actually produced, yet with significant differences. The spaceship—designed with a low-budget production in mind—was a small craft called the Snark. In the original script the ship's crew -- including the Ripley character -- are all male. Actor Tom Skerritt was originally cast as Ripley, but during script development the character was re-cast as a woman, reportedly at the insistence of producer Alan Ladd Jr -- a decision which proved crucial to the film's success.
Read more at Wikipedia.org