Tom Clancy's Rainbow Six: Lockdown is the fourth game in the Rainbow Six series. The initial design and PlayStation 2 version were developed by Red Storm Entertainment and the Xbox version was developed by the Ubisoft Montreal studio. Both are published by Ubisoft. The Mobile phone version was released on June 9, 2005; the PlayStation 2 and Xbox versions were released on September 6; the GameCube version was released on September 27; and a version for Windows was released on February 16, 2006.