Acronym standing for Integrated High Performance Turbine Engine Technology. A joint team of DARPA and USAF engineers working for a common jet engine platform for the Joint Strike Fighter or JSF. The engine platform would be capable of V/STOL / heave, MACH cruise, and thrust vectoring.
To perform these feats, new materials, concepts and technology will need to be fashioned.
Many IHPTET engine functions can be seen in the engines of the F-22 Raptor, which can perform heave via thrust vectoring, and MACH cruise or sustained (hours-long) flight at speeds greater than the speed of sound.