Winds in OB-type stars

The International Ultraviolet Explorer satellite has made a tremendous contribution to the study of hot-star winds. Its long lifetime has resulted in the collection of ultraviolet spectra for a large sample of OB stars. Its unique monitoring capability has enabled detailed time-series analyses to investigate the stellar-wind variability for individual objects. IUE has also been a major driver for the development of the radiation-driven-wind theory; the synergy between theory and observations is one of the main reasons for the large progress that has been made in our understanding of hot-star winds and their impact on the atmospheres and evolution of massive stars.