  We briefly review attempts to construct string theories that yield the
standard model, concentrating on models with a geometric interpretation.
Calabi-Yau compactifications are discussed in the context of both the weakly
coupled heterotic string and the strongly coupled version, heterotic M-theory.
Similarly, we consider orbifold compactifications of weakly coupled heterotic
theory and of Type II theories in the presence of D-branes. The latter allows a
"bottom-up" construction that so far seems the most natural and direct route to
the standard model.
