  We review techniques simplifying the analytic calculation of one-loop QCD
amplitudes with many external legs, for use in next-to-leading-order
corrections to multi-jet processes. We explain how a supersymmetry-inspired
organization works well in conjunction with other tools, namely the color and
helicity decompositions of amplitudes, and the constraints imposed by
perturbative unitarity and collinear singularities. String theory seems most
useful as a heuristic guide. Using these techniques, the complete set of
one-loop five-parton QCD amplitudes, as well as certain sequences of special
helicity amplitudes with an arbitrary number of external gluons, have been
obtained.
