(partial) Preface. I. Overview of EUV Observations. Extrapolations from SXR surveys. II. Sources of EUV Radiation. White dwarfs. Cool stars. Hot stars. Cataclysmic variables. Compact objects. Extragalactic objects. Solar system objects. Interstellar Medium. III. Interstellar Absorption. IV. Innovative EUV Instrumentation. V. Future EUV Missions. Appendix: Catalog of known EUV sources. References. Index.