Quantum Dynamics, both reversible and irreversible, gives rise to product systems. Arveson’s discovery that reversible dynamics on B(H), the algebra of all operators on a Hilbert space H, leads to product systems of Hilbert spaces, marked the begin of a still increasing amount of literature where product systems are used in order to understand better the quantum dynamics that produced them. This intimate relationship between quantum dynamics and product systems has been generalized in many ways, often leading to product systems of Hilbert modules. For product systems of Hilbert spaces it is impossible to give an approximately complete description of the known constructions in just one talk. And still many questions (in particular about classification) are open. The scope of our talk is to make an attempt to present a picture of the state of the art regarding product systems of Hilbert modules. This may appear as a contradiction. But as we intend to put emphasis on those aspects that distinguish the module case from the scalar case, and as the theory in the module case is less developed, we hope the attempt might be successful.