A summary is given of the IAU Colloquium No 191 “The Environment and Evolution of Binary and Multiple Stars.” This conference was held in Mérida, Mexico during February 2003 and dedicated to Dr. Arcadio Poveda for his major contributions to binary- and multiple-star systems and dynamics. The conference was organized to discuss the major developments that are occurring in the fields of binary- and multiple-star formation, evolution, dynamics, and the environments where they form and evolve.