Aliens versus Predator

Aliens versus Predator is a science fiction first-person computer game developed by Rebellion and published by Sierra. It was officially released for Windows and Mac in 1999, followed by an unofficial port to Linux in 2001, following Rebellion's public release of the game's source code. A sequel, Aliens versus Predator 2, was developed by Monolith Productions, and released by Sierra in 2001.