High luminosity X-ray binaries: IUE results

The contribution of UV spectroscopy to the understanding of massive X-ray binaries, is reviewed. Results are given in the context of normal stars and binaries. The IUE results have enabled a greater understanding of the effects of accretion disks and X-ray heating in the systems, and provide absolute fluxes and luminosities. High-dispersion data reveal the effects of X-rays on the structure of hot star winds. Some current problems are indicated, and the future roles of IUE and ST discussed in their resolution.