X-ray fluorescence, or X-ray spectrometry, is a dynamic analytical method; it undergoes constant change and improvement. Because of the early successes for the analysis of difficult samples such as metals, minerals and other solid materials, the technique was widely accepted in industrial applications. This occurred prior to the onset of large government funding to develop instrumental methods such as was provided for the development of inductively coupled plasma emission spectrometry. As a result, many of the important developments in XRF in North America have resulted from research and development by the instrumentation vendors and developments from Industrial and mission oriented government laboratories. There are exceptions, of course.