The M1919 Browning is a .30 caliber medium machine gun widely used during the 20th century, especially during World War II, the Korean War, and the Vietnam War. An air-cooled development of the standard US machine gun of World War I, the John M. Browning-designed M1917, the M1919 saw service as a light infantry, coaxial, mounted, aircraft, and anti-aircraft machine gun by the U.S. and many other countries. Although it began to be superseded by newer designs, such as the M60, in the later half of the century, it remained in use in many North Atlantic Treaty Organization (NATO) countries and elsewhere for much longer.