  We review a series of works where the fundamental master equation is used to
develop a microscopical description of evolution of non-equilibrium atomic
distributions in alloys. We describe exact equations for temporal evolution of
local concentrations and their correlators as well as approximate methods to
treat these equations, such as the kinetic mean-field and the kinetic cluster
methods. We also describe an application of these methods to studies of
kinetics of L1_0 type orderings in FCC alloys which reveal a number of peculiar
microstructural effects, many of them agreeing well with experimental
observations.
