This volume is the status report of the international community of practitioners of x-ray microscopy. It contains the reviews and work presented at the 6th International Conference on X-Ray Microscopy held in Berkeley, 2-6 August 1999. The techniques are being applied to biological imaging where, for example, special labeling can reveal the location of specific proteins in cells, while cryogenic sample handling prevents x-ray damage to cells. These techniques can also be used to analyze objects on a 10 nm size scale, allowing the study of their physical and chemical state. For example, chemical processes in the environment can be examined on the surfaces of microscopic particulate matter. The availability of several new soft x-ray synchrotron light sources around the world is facilitating the development of new applications. This conference showed that large new programs have become productive at these new synchrotron sources.