  We present a preliminary set of updated NLO parton distributions. For the
first time we have a quantitative extraction of the strange quark and antiquark
distributions and their uncertainties determined from CCFR and NuTeV dimuon
cross sections. Additional jet data from HERA and the Tevatron improve our
gluon extraction. Lepton asymmetry data and neutrino structure functions
improve the flavour separation, particularly constraining the down quark
valence distribution.
