A range of topics are covered in this volume, from supernovae to active galactic nuclei, cosmic gamma rays to neutrinos and dark matter. The basic emphasis is on physics/astrophysics and experimental/observational techniques, scientific implications of current results and prospects for future advances. The fields examined are developing rapidly, as is the exploration of our high energy universe, with exciting discoveries. What unifies much of the data is the idea of particle acceleration to enormous energies and the subsequent interactions of the particles with the local medium.