The contributions in this volume provide a snapshot of the latest research and future plans for space-borne and ground-based experiments dedicated to the observation of the gamma-ray sky. The articles are authored by both seasoned veterans of the first dedicated gamma-ray missions, and young scientists entering the fascinating field of gamma-ray astrophysics. With the advent of gamma-ray instrumentation on spacecraft and large and sensitive ground-based detectors, new and unexpected phenomena have been discovered, such as gamma-ray bursts and gamma-ray emission from blazars. The immense...