Kanon (カノン, Kanon) is a Japanese visual novel developed by Key and released on June 4, 1999. The original version, made for the PC, was rated 18 or older by Japan's Ethics Organization of Computer Software, but an all ages version was released on in January 2000. Subsequent general-audience versions were produced for the Dreamcast, PlayStation 2, and PlayStation Portable. Later, the Kanon Standard Edition was released for the PC, playable as a DVD-ROM in adult and all-ages versions. The Kanon Standard Edition incorporates the few extra graphics added to the all-ages version of the game. Both Standard Editions add support for Windows 2000/XP and other technical changes such as more save slots. Otherwise, the all-ages Kanon Standard Edition is the same as the original all-ages version released for the game.