The Mikoyan-Gurevich MiG-21 (NATO reporting name "Fishbed") is a supersonic jet fighter aircraft, designed and built by the Mikoyan-Gurevich Design Bureau in the Soviet Union. It was popularly nicknamed "balalaika", from the aircraft's planform-view resemblance to the famous Russian stringed musical instrument or oÅÃ³wek (English: pencil) by Polish pilots due to the shape of its fuselage. Early versions are considered second-generation jet fighters, while later versions are considered to be third-generation jet fighters. Some 50 countries over four continents have flown the MiG-21, and it still serves many nations a half-century after its maiden flight. The fighter has the distinction of holding a number of aviation records, including 1) most produced supersonic jet aircraft in aviation history, 2) most produced combat aircraft since World War II, and 3) longest production run of a combat aircraft. It has been estimated that more than 10,000 MiG-21s were built.