  We compare different schemes for the treatment of heavy quark production in
Deep-Inelastic Scattering (DIS). For fully-integrated quantities such as
$F_{2}(x,Q^{2})$, we advocate the use of the General-Massive
Variable-Flavor-Number (GM-VFN) scheme; we present some results showing the
progress of a Next-to-Leading Order calculation in this scheme. For
differential quantities, the Fixed-Flavor-Number (FFN) scheme provides a more
appropriate starting point. We present a new calculation of the azimuthal
distribution of charm quark production in DIS. All results have been obtained
using a Monte Carlo program under development.
