Blastwave Jet Company: Information on a little known bent pipe blast wave or pulse jet engine.
NASA General Aviation Propulsion Program: Program to improve small airplane engines.
Turbo & Jet Engine Research Laboratories: Israel Institute of Technology. Does theoretical and experimental R&D work in jet engines and gas turbines, for high-efficiency low NOx small-medium engines.
Ultra-Efficient Engine Technology Program: NASA sponsored program to research and develop next generation aircraft engines.