During the last few years it has become increasingly clear that a very wide variety of state-based dynamical systems, such as transition systems, automata, process calculi and class-based systems can be captured uniformly as coalgebras. Moreover, the theory and applications of coalgebras is developing into a field of interest in its own right, presenting a deep mathematical foundation, a growing range of applications and interactions with various other areas, such as reactive and interactive system theory, object-oriented and concurrent programming, formal system specification, modal logic, dynamical systems, control systems, category theory, algebra, analysis, and so on.