  We present a derivation of the threshold resummation formula for the
Drell-Yan rapidity distribution. Our argument is valid for all values of
rapidity and to all orders in perturbative QCD and can be applied to all
Drell-Yan processes in a universal way, i.e. both for the production of a
virtual photon \gamma^{*} and the production of a vector boson W^{\pm}, Z^{0}.
We show that for the fixed-target experiment E866/NuSea used in current parton
fits, the NLL resummation corrections are comparable to NLO fixed-order
corrections and are crucial to obtain agreement with the data.
