Joint Strike Fighter (JSF) is a development and acquisition program intended to replace a wide range of existing fighter, strike, and ground attack aircraft for the United States, the United Kingdom, Canada, and their allies. After a competition between the Boeing X-32 and the Lockheed Martin X-35, a final design was chosen based on the X-35. This is the F-35 Lightning II, which will replace various tactical aircraft, including the US F-16, A-10, F/A-18, AV-8B and British Harrier GR7 & GR9s, and the Canadian CF-18.