This Cost Action coordinates the European-wide research effort to understand problems associated with risk in such fields as quantitative finance, food safety, health, and social sciences. The concept underlying these phenomena is that of growing networks exhibiting "small-world" and 'scale-free' behavior. The former label denotes a high degree of local clustering of such networks providing short path lengths between all pairs of verticals, while the latter signifies that the probability that a node in the network is connected to k other nodes decays as a power law. SCL's aim in joining this Action is to gain additional insight into the basic ingredients that determine network topology, and to study various dynamical rules on these networks as well as their interplay with geometry. The World Wide Web is a manifestation of the largest global social network for which quantitative topological information is currently available and represents an important test bed for ideas about growing networks.