The JSF is an advanced attack aircraft being developed in the USA, and Britain has expressed an interest in it. There were two companies competing for the contract: Lockheed-Martin (X-35), and Boeing (X-32). Lockheed-Martin's design has trapezoidal wings and lateral inlets similar to the company's F-22. It has an F-15 like wing structure. There is a planned STOVL variant for the Royal Navy, which has enlarged leading- and trailing-edge flaps for carrier use. 

Boeing's original JSF had a delta configuration one-piece wing, and was a STOVL design, but was then changed to be more like Lockheed-Martin's design, with a conventional wing. It is quite short, with a length of 47 ft, a wingspan of 36 ft, and a height of 13 ft. It will carry about 16,000 lbs. of internal fuel in its one-piece wing, eliminating the need for external fuel tanks. The nose profile is notably strange, with an inlet under the body, set back from the main nose and starting level with the front of the cockpit canopy, making the main nose look like a 'beak'.

The Joint Strike Fighter will use JDAM (Joint Direct Attack Munition), and JASSM (Joint Air-to-Surface Standoff Missile). JDAM has a GPS/Inertial Guidance System which is programmed just before release, with trajectory calculated by the JSF's weapons computers. It also compensates for errors caused by wind and other factors. The 2,000lb (900kg) bomb is not as accurate as an LGB, but is much cheaper. It is designated GBU-31. JASSM (AGM-158) has a range of 100nm (185km), a 1,000lb warhead and a precision guidance system. It is essentially a cheap, advanced ALCM. The JSF is due to replace the Harrier & Sea Harrier in 2012.

Lockheed-Martin X-35

The Lockheed-Martin X-35 won the JSF contract in mid-2001, & as a result will enter service with the USAF, USN, USMC, RAF & RN between 2008 & 2012. British JSFs will operate from a new type of aircraft carrier, two of which are currently being built. The JSF will replace the Sea Harrier on these new carriers, & will be complemented by an AEW aircraft, probably an EH-101 Merlin or a V-22 Osprey. The RAF's Harrier GR.7s will also be replaced by JSFs.

Boeing X-32

The Boeing X-32 lost the JSF contract to the X-35, & as a result will never see service. The X-32 was beaten into the air by the X-35, & also experienced more technical difficulties. The X-32 never really got a chance to prove itself, but would have lost the contract anyway, the aircraft having inferior performance & higher unit price than its competitor.