  We discuss the recent developments in inclusive decays of hadrons containing
a heavy quark. The subject is approached in a model independent way using an
operator product expansion for the time-ordered product of weak currents. We
discuss the extraction of the weak mixing angle $|V_{cb}|$ from inclusive
semileptonic $B$ decays and the application of these techniques to the endpoint
of the $e^-$ spectrum in $B\rightarrow X_ue\nu$. We also suggest that the
comparison of inclusive semileptonic widths for $D_s$ and $D$ mesons will give
an indication of the consistency of this approach in charm decays. \bigskip
{\it Invited talk presented at the "Intersections of Particle and Nuclear
Physics" conference, St Petersburg, Florida, 31 May to 6 June, 1994.}
