An International Conference entitled "Close Binaries in the 21^st Century: New Opportunities and Challenges," was held in Syros island, Greece, from 27 to 30 June, 2005.

There are many binary star systems whose components are so close together, that they interact in various ways. Stars in such systems do not pass through all stages of their evolution independently of each other; in fact their evolutionary path is significantly affected by their companions. Processes of interaction include gravitational effects, mutual irradiation, mass exchange, mass loss from the system,...