35 years of EDS software.

The computerized multichannel analyzer running software specifically designed for X-ray analysis appeared very early in the commercialization of the energy dispersive X-ray spectrometer (EDS) and, like the solid-state X-ray detector itself, was built on a technology foundation originally developed for nuclear spectroscopy. However, software techniques employed for gamma-ray spectra could not accommodate the continuum component of EDS spectra, and a new approach was required. Least-squares fitting with "top-hat" filtered spectra proved to be an effective solution that is still widely used today. Though modern computer technology has subsequently contributed greatly to the speed and convenience of present-day EDS software, it seems that the achievable accuracy and precision of spectrum analysis has not fundamentally improved, and most of the early challenges are still quite relevant, although they may appear in new guises. The availability of the high speed silicon drift detector, however, may provide both the incentive and the data precision to drive future advances. This article traces the formative years of EDS software from the personalized perspective of a participant. Factors that shaped the development of the industry are identified, and future directions are speculated.