A double-pronged approach makes this book an extremely useful addition to the literature on this highly relevant contemporary topic. Addressing two basic areas of application for algebras and coalgebras - as mathematical objects as well as in the context of their application in computer science - the papers cover topics such as abstract models and logics, specialised models and calculi, algebraic and coalgebraic semantics, and system specification and verification. The book is the refereed proceedings of the second CALCO conference, held in August 2007 in Norway.