The Grumman Panther is rightly well-regarded for its extensive service in the Korean War. But the Panther was essentially obsolete on delivery thanks to the emergence of the swept wing Sabre and MiG-15.
The US Navy had plenty of ambitious plans for high performance, swept wing carrier fighters. But ambitious plans take time to come to fruition. So the Navy asked ever-reliable Grumman to graft a swept wing onto the Panther. This is the story of that aircraft: the largely forgotten F-9 Cougar. A solid, but unremarkable jet that took the Navy into the swept wing era.
Sources:
"F-9F Cougar In Detail And Scale" by Bert Kinzey is the usual fare of great photos with slightly lumpy text. Still well worth picking up, albeit sadly long out of print
"Naval Fighters Number 66: Grumman F9F-6/7/8. Part 1" by Corwin "Corky" Meyer contains wonderful first hand recollections and technical information from the legendary test pilot. The text is sometimes hard to follow though, so I would say it is one for the purists!