The General Dynamics F-16 Fighting Falcon, also known as the Viper, evolved from a 1972 USAF lightweight fighter prototype program to create a small, low-cost, air-superiority day fighter designed for high performance and ease of maintenance; it achieved combat-ready status in October 1980. Since then, 21 foreign nations including Belgium, Denmark, Turkey, Egypt, and Israel have the F-16, making it the most popular fighter in the world. The varied national insignia, squadron markings, and camouflage of these international F-16s are depicted in full color.