The ESO workshop Multiple Stars across the H-R Diagram was held in Garching on 12 15, July 2005. The topics included observations of multiple stars from ground and space, dynamical and stellar evolution in multiple systems, e?ects of the environment on multiplicity, formation and early e- lution of multiple stars, and special components of multiple stars (chemically peculiar stars, blue stragglers, brown dwarfs, etc.). Stars show a marked tendency to be in systems of di?erent multiplicity, 7 ranging from simple binaries and triples to globular clusters with N?10 . Modern observations give a...