  This paper reviews the current understanding of double neutron star and
neutron star black hole binaries. It addresses mainly (nuclear) astrophysics
aspects of compact binary mergers and thus complements recent reviews that have
emphasized the numerical relativity viewpoint. In particular, the paper
discusses different channels to release neutron-rich matter into the host
galaxy, connections between compact binary mergers and short Gamma-ray bursts
and accompanying electromagnetic signals.
