  World-wide, several detectors currently running or nearing completion are
sensitive to a prompt core collapse supernova neutrino signal in the Galaxy.
The SNEWS system will be able to provide a robust early warning of a
supernova's occurrence to the astronomical community using a coincidence of
neutrino signals around the world. This talk describes the nature of the
neutrino signal, detection techniques and the motivation for a coincidence
alert. It describes the implementation of SNEWS, its current status, and its
future, which can include gravitational wave detectors.
