  We present the one-loop helicity amplitudes for processes involving a vector
boson V (V=W,Z, or gamma^*) and four massless quarks, 0 to V q-bar q Q-bar Q,
where V couples to a massless lepton pair. These amplitudes are required for
next-to-leading order O(alpha_s^3) numerical programs for four-jet production
at e^+ e^- colliders, for W, Z or Drell-Yan production in association with two
jets at hadron colliders, and for three-jet production in deeply inelastic
scattering experiments. We obtained the amplitudes presented here by using
their analytic properties to constrain their form.
