Extracting the strange density from xF3

We present a QCD analysis of the strange and charm contributions to the neutrino deep inelastis structure function xF3. We show that next-to-leading order effects, which are relatively important for F2, play a lesser role in the case of xF3. The neutrino-antineutrino difference xF3ν - xF3ν provides a new determination of the strange density, which exhibits some advantages with respect to other traditional methods.