This volume, marking the 20th Anniversary of the International School of Cosmic Ray Astrophysics, provides a wide-ranging overview of modern astrophysics — from the infra-red to X-rays and γ-rays, from neutrinos to galactic cosmic rays, and from shock wave acceleration to cosmology. The separate topics contain both background information and the newest results in the field, making the discussion suitable for the nonexpert and the expert alike. Featured are high energy neutrinos (including the new generation of experiments coming on line), new results from X-ray astronomy and from the infra-red, particle acceleration in astrophysical plasmas, new results on the composition of cosmic rays (spanning six decades in energy), and cosmology.