Progress in QCD next-to-leading order calculations

I review progress related to the calculation of QCD jet cross sections at the NLO accuracy. After a short introduction into the theory of NLO calculations, I discuss two recent developments: the calculation of twoand three-jet leptoproduction at the NLO accuracy and the extension of the dipole subtraction method for computing NLO corrections for processes involving massive partons. Jet cross sections at the NLO accuracy consist of the first two terms of the perturbative expansion in the strong coupling, σ = σ + σ = ∫ m dσ + σ . (1) The leading order cross section is the integral of the fully exclusive Born matrix element of m final-state partons over the available phase space. The NLO correction is a sum of two terms: the real correction is the integral of the Born matrix element of m + 1 finalstate partons and the virtual correction is the integral of the interference term between the Born-level and one-loop amplitudes of m final state partons, σ = ∫