  I shortly review the present status of the theoretical calculations of
epsilon'/epsilon and the comparison with the present experimental results. I
discuss the role of higher order chiral corrections and in general of
non-factorizable contributions for the explanation of the Delta I = 1/2
selection rule and direct CP violation in kaon decays. Still lacking reliable
lattice calculations, analytic methods and phenomenological approaches are
helpful in understanding correlations among theoretical effects and the
experimental data. Substantial progress from lattice QCD is expected in the
coming years.
