  In this talk, we present the first, numerically stable, results for the
one-loop amplitudes needed for computing W,Z + 3 jet cross sections at the LHC
to next-to-leading order in the QCD coupling. We implemented these processes in
BlackHat, an automated program based on on-shell methods. These methods scale
very well with increasing numbers of external partons, and are applicable to a
wide variety of problems of phenomenological interest at the LHC.
