The rapid advance and falling costs of computing power and data storage during the last 40 years have greatly enhanced the data reduction speed and analytical capacity of energy dispersive spectroscopy (EDS) systems. At the same time, the solid state X-ray detector [until recently, the Si(Li) diode] has seen performance increases due to the use of advanced materials and processing techniques. In addition, the performance of the electronic components (field effect transistor, preamp, and pulse processor) of an EDS system has been constantly improved. These technology advances have resulted in improved spectral quality, excellent light element detection, and increased count rate performance. The results have been truly remarkable and driven by the needs of the analyst. This article will summarize the progress made in these areas in the last 40 years and make a brief reference to prospects for future development in EDS system performance.