Calculations to next-to-leading order in QCD of Standard-Model processes provide the leading quantitatively reliable predictions. They are a prerequisite for comparisons to experimental data. The BlackHat collaboration has been pushing the high-multiplicity frontier in such calculations. I review some of the on-shell methods used for the one-loop amplitudes needed for these calculations. I present the next-to-leading predictions for W and Z production in association with three and four jets at the LHC; preliminary results for W production in association with five jets; and results for pure four-jet production. I also discuss applications to various LHC searches.