Abstract
The author presents a review of studies of X-ray emission from massive O, B, and WR stars in open clusters based mostly on data from the ROSAT X-ray observatory. Such open cluster studies can address the dependence of the X-ray emission from massive stars on stellar age and metallicity, on local environment, and explore questions of the generation of diffuse X-ray emission and cluster history and the influence of X-ray emission on the parent molecular cloud.
