  The recent discoveries of high-energy astrophysical neutrinos and
gravitational waves have opened new windows of exploration to the Universe.
Combining neutrino observations with measurements of electromagnetic radiation
and cosmic rays promises to unveil the sources responsible for the neutrino
emission and to help solve long-standing problems in astrophysics such as the
origin of cosmic rays. Neutrino observations may also help localize
gravitational-wave sources, and enable the study of their astrophysical
progenitors. In this work we review the current status and future plans for
multi-messenger searches of neutrino sources.
