  The positive weight next-to-leading-order (NLO) matching scheme (POWHEG) is
applied to Drell-Yan vector boson production in the Herwig++ Monte Carlo event
generator. This approach consistently combines the NLO calculation and parton
shower simulation, without the production of negative weight events. The
simulation includes a full implementation of the truncated shower required to
correctly describe soft emissions in an angular-ordered parton shower, for the
first time. The results are compared with Tevatron W and Z production data and
predictions for the transverse momentum spectrum of gauge bosons at the LHC
presented.
