  We review sharpening methods for finite volume schemes, with an emphasis on
the basic structure of sharpening methods. It covers high order methods and non
linear techniques for linear advection, Glimm's method, anti-diffusion
techniques, the interaction of these techniques with the PDE structures.
Additional approaches like level sets, interface reconstruction and Vofire are
also discussed. We also present the algorithmic structure of the downwind
method for a simple two components problem.
