The list of aircraft of World War II includes all of the aircraft used by countries which were at war during World War II from the period between when the country joined the war and the time the country withdrew from it, or when the war ended. Aircraft developed but not used operationally in the war are in the prototypes section at the bottom of the page. Prototypes for aircraft that entered service under a different design number are ignored in favor of the version that entered service. If the date of an aircraft's entry into service or first flight is not known, the aircraft will be listed by its name, the country of origin or major wartime users. Aircraft used for multiple roles are generally only listed under their primary role unless specialized versions were built for other roles in significant numbers. Aircraft used by neutral countries such as Spain, Switzerland and Sweden (or countries which did no significant fighting such as most of those in South America) are not included.