Collective dynamics under nonequilibrium conditions is ubiquitous in natural processes and technology. It greatly influences all fields of science, ranging from physics, chemistry and biology to engineering. Different approaches to study nonequilibrium collective dynamics have been developed in different disciplines, in particular in hard and soft condensed matter and biological physics. The conference NECD15 aims at bringing together specialists in these fields and to stimulate an intensive exchange of methods and ideas among them. NECD15 is organized by the research training group GRK1558.