Halo is a
military science fiction first-person shooter video game franchise created by
Bungie and now managed and developed by
343 Industries, a subsidiary of
Microsoft Studios. The series centers on an interstellar war between humanity and a theocratic alliance of aliens known as the
Covenant. The Covenant, led by their religious leaders called the
Prophets, worship an ancient civilization known as the
Forerunners, who perished in combat with the parasitic
Flood. The central focus of the franchise builds off the experiences of
Master Chief John-117, one of a group of
supersoldiers codenamed
Spartans, and his
artificial intelligence (AI) companion,
Cortana. Other characters, such as Noble Six from , are also introduced in the series. The term "Halo" refers to the
Halo rings: large, habitable superweapons that were created to destroy the parasitic Flood. They are similar to the
Orbitals in
Iain M. Banks'
Culture novels, and to author
Larry Niven's
Ringworld concept.