WarBirds is a massively multiplayer online and offline World War II simulation, published by iEntertainment Network. The game includes an air combat flight simulator as well as a simulator for tanks and other ground vehicles. WarBirds was originally developed in 1995 (as Confirmed Kill) by Interactive Creations of Grapevine and inspired a fan following, conventions and a book titled WarBirds: The Story so far. Source: Wikipedia, "WarBirds", available under the CC-BY-SA License.