The Boeing X-35 was a prototype aircraft developed for the United States' Joint Strike Fighter (JSF) program. It was designed to demonstrate advanced technologies for a versatile fighter jet capable of vertical takeoff and landing. The X-35 competed against the Lockheed Martin X-32 in a bid to create a next-generation multirole combat aircraft. The X-35 featured a unique design with a single engine and advanced stealth capabilities. It successfully completed various flight tests, showcasing its agility and performance. Ultimately, the X-35 evolved into the F-35 Lightning II, which is now used by multiple branches of the U.S. military and allied nations.