JSF means Joint Strike Fighter
The JSF program has been launched to replace the combat devices with a new next-generation combat device. There was some battle between Boeing (X-32) and Lockheed Martin (X-35), and the winner of this fight has become Lockheen Martin, and the JSF is actually the Lockheed Martin JSF F-35 Lightning II. Read news about the JSF at Jsfnieuws
F-35 JSF Tribute