  Supersymmetry and Grand Unification are the two most promising directions for
physics beyond the Standard Model. They receive indirect experimental support
from the apparent lightness of the Higgs boson, the values of the gauge
couplings measured at LEP and elsewhere, and the persistent solar neutrino
deficit. Phenomenological constraints and theoretical models constrain
predictions in interesting ways. All these ideas may be embedded in string
theory, which is shown by newly-discovered dualities to possess
previously-unsuspected richness and simplicity.
