Video games developed by Key, a Japanese visual novel video game development studio and brand under the publisher VisualArt's, are initially published by VisualArt's and released for Microsoft Windows personal computers; consumer ports are published by Interchannel and Prototype. Key released their debut title, Kanon, in 1999, followed by their second title, Air, in 2000. Both Kanon and Air were initially released as adult games, but Key released their third game, Clannad, in 2004 with a rating of approval for all ages. Nine more games have been released since then. Key released a box set called "Key 10th Memorial Box" in July 2009 containing six of Key's visual novels with a rating for all ages.
