Gun is a Western-themed action-adventure video game developed by Neversoft and published by Activision for the PlayStation 2, Xbox, GameCube, Microsoft Windows, and Xbox 360 in 2005. The PlayStation Portable version was released a year later under the title Gun: Showdown, this version features new side-missions, a multiplayer mode, and other additions that were not available in the console versions.

Activision Publishing, Inc. is an American video game publisher based in Santa Monica, California. It serves as the publishing business for its parent company, Activision Blizzard, and consists of several subsidiary studios. Activision is one of the largest third-party video game publishers in the world and was the top United States publisher in 2016.