  We consider direct diphoton production in hadron collisions, and we compute
the next-to-next-to-leading order (NNLO) QCD radiative corrections at the
fully-differential level. Our calculation uses the $q_T$ subtraction formalism
and it is implemented in a parton level Monte Carlo program. The program allows
the user to apply arbitrary kinematical cuts on the final-state photons and the
associated jet activity, and to compute the corresponding distributions in the
form of bin histograms. We present selected numerical results related to Higgs
boson searches at the LHC and corresponding results at the Tevatron.
