Directing the exhaust of a turbojet engine through an ejector pump can significantly increase the jet thrust. This paper is a review of recent advances in the development of thrust augmenting ejectors for VSTOL aircraft. Progress in developing a theory of ejector operation, and related efforts in analysis and prediction will be summarized. Studies of turbulent mixing and duct design which have led to improvements in ejector performance will also be described. Finally, research problems of current interest and the likely direction of future airplane programs will be discussed.