Originally released in 1990, the Civilization series is the most highly sold grouping of strategy games ever (over 4 million copies). Sid Meier, original creator of Civilization created a genre that will never cease to give gamers joy for years to come. Civilization II (released in 1996) quickly became one of the most highly sold strategy games ever. Newer titles include Civilization : Call to Power and Call to Power II by Activision [under license from Microprose] and Civilization III [by Firaxis]. Several add-ons have been released for Civilization II and CivNet, a multiplayer of Civilization for Windows.