  What did we learn out of SN1987A neutrino observations? What do we still need
for a full understanding? We select important issues debated in the literature
on SN1987A. We focus the discussion mostly on the relevance of certain data
features; on the role of detailed statistical analyses of the data; on the
astrophysics of the neutrino emission process; on the effects of oscillations
and of neutrino masses. We attempt to clearly identify those issues that are
still open.
