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, Italy, Canada, Australia, the Netherlands, Denmark, Norway, and formerly Turkey. After a competition between the Boeing X-32 and the Lockheed Martin X-35, the latter aircraft was selected for a contract award and developed into the F-35 Lightning II, which will replace various tactical aircraft, including the US F-16, A-10, F/A-18A-D, AV-8B, EA-6B and British Harrier GR7, GR9s and Tornado GR4. The projected average annual cost of the program is $12.5 billion in 2012 with an estimated cost in 2024 of $2 trillion over its lifespan.