  Gamma-ray bursts are the most luminous explosions in the Universe. They
appear connected to supernova remnants from massive stars or the merger of
their remnants, and their brightness makes them temporarily detectable out to
the larges distances yet explored in the Universe. After pioneering
breakthroughs from space and ground experiments, their study is entering a new
phase with observations from recently launched satellites, as well as the
prospect of detections or limits from large neutrino and gravitational wave
detectors. The interplay between such observations and theoretical models of
gamma-ray bursts and related objects is reviewed.
