The articles in this book are written versions of talks presented at a conference organized by the TMR network in Corfu. The main theme of the conference was the interconnection between string theory and gauge theory. These very recent developments draw from many aspects of string theory, supergravity and supersymmetric gauge field theory. For students starting their research there is a great deal of background material that they have to absorb in order to be able to follow current developments. With this in mind the editors have included pedagogical lectures on background material and recent...