  In the last decade, enormous progress has been achieved in the understanding
of the various facets of coalescing double neutron star and neutron black hole
binary systems. One hopes that the mergers of such compact binaries can be
routinely detected with the advanced versions of the ground-based gravitational
wave detector facilities, maybe as early as in 2016. From the theoretical side,
there has also been mounting evidence that compact binary mergers could be
major sources of heavy elements and these ideas have gained recent
observational support from the detection of an event that has been interpreted
as a "macronova", an electromagnetic transient powered by freshly produced,
radioactively decaying heavy elements. In addition, compact binaries are the
most plausible triggers of short gamma-ray bursts (sGRBs) and the last decade
has witnessed the first detection of a sGRB afterglow and subsequent
observations have delivered a wealth of information on the environments in
which such bursts occur. To date, compact binary mergers can naturally explain
most --though not all-- of the observed sGRB properties. This article reviews
major recent developments in various areas related to compact binary mergers.

High Energy Astrophysical Phenomena