The αS dependence of parton distributions

We perform next-to-leading order global analyses of deep inelastic and related data for different fixed values of αS(MZ2). We present sets of parton distributions for six values of αS in the range 0.105 to 0.130. We display the (x, Q2) domains with the largest parton uncertainty and we discuss how forthcoming data may be able to improve the determination of the parton densities.