Stargate literature comprises the novels and short stories in the Stargate franchise fictional universe (based on either the original Stargate film or the Stargate SG-1, Stargate Atlantis and Stargate Universe television shows) as well as non-fiction devoted to the franchise. Stargate literary works follow no strict continuity with the series or each other, and are often considered to be non-canon. This is evident in the fact that there is a period of roughly a year between the original idea for a novel and the finalised product, causing problems for authors as they are unaware as to how the franchise will develop and change during the writing process. Despite this, the editors of Stargate literature function as the medium between the author and the production company.