  We review recent progress in the theory of jet production, with particular
emphasis on the possibility of 1) powerful jets being produced in the first few
seconds after collapse of a supernova core and 2) those jets being responsible
for the asymmetric explosion itself. The presently favored jet-production
mechanism is an electrodynamic one, in which charged plasma is accelerated by
electric fields that are generated by a rotating magnetic field anchored in the
protopulsar. Recent observations of Galactic jet sources provide important
clues to how {\em all} such sources may be related, both in the physical
mechanism that drives the jet in the astrophysical mechanisms that create
conditions conducive to jet formation. We propose a grand evolutionary scheme
that attempts to unify these sources on this basis, with MHD supernovae
providing the missing link. We also discuss several important issues that must
be resolved before this (or another scheme) can be adopted.
