In the early 1990’s FOX did see promise in developing Alien vs. Predator, then a successful comic book series created by Dark Horse Comics. After reviewing a script treatment, FOX commissioned Peter Briggs to write a full screenplay. While it was never produced, the script became very popular, especially within Internet fan circles. For an excellent interview with Peter Briggs discussing his involvement with Alien vs. Predator, (Both his script and the 2004 movie) visit Bloody-Disgusting. A must read for any fan.
When interest was renewed in an Alien vs. Predator film in the early 2000’s, a script for the film was commissioned by Fox and it was up to James DeMonaco and Kevin Fox, to deliver a new draft. However, John Davis(producer) decided to take the project in a different direction (not based on the comic book series, which DeMonaco and Fox had done.) The proposed storyline (from the now defunct 4Filmmakers website): “A man becomes a Predator after discovering a crashed Predator ship. His team of researchers use the Alien eggs to create an environment of conflict to lure the Predators back to study their technology and prolong his life.” The date of the finished first draft was January 2002.
Paul W.S. Anderson was given the director’s chair at about this time, and he started to write his own work into the movie. An interesting situation with the final writing credits now existed. From Wikipedia: “The writing credits submitted by the studio to the WGA recommended that Peter Briggs and Paul W.S. Anderson be credited for the story, while Anderson and Shane Salernoget the screenplay credit. Instead, the WGA denied any sort of credit to Briggs or Salerno, and instead gave co-story credit to original Alien writers Dan O’Bannon and Ronald Shusett on the rationale that some story elements were based on a deleted scene from that film. Shocked at this decision, the studio offered Salerno an executive producer’s credit, but he turned it down.