The Boeing 707 is a four-engine narrow-body commercial passenger jet airliner developed by Boeing in the early 1950s. Its name is most commonly pronounced as "Seven Oh Seven". The first airline to operate the 707 was Pan American World Airways, inaugurating the type's first commercial flight on October 26, 1958. Boeing delivered a total of 1,011 Boeing 707s including a smaller, faster model of the aircraft that was marketed as the Boeing 720.