  The QCD coupling $\alpha_s$ is extracted from the energy evolution of the
first two moments (multiplicity and mean) of the parton-to-hadron fragmentation
functions at low fractional hadron momentum $z$. Comparisons of the
experimental $e^+e^-$ and deep-inelastic $e^\pm$p jet data to our NNLO$^*$+NNLL
predictions, allow us to obtain $\alpha_s(m_{_{\rm Z}})$ =
0.1205$\pm$0.0010$^{+0.0022}_{-0.0000}$, in excellent agreement with the
current world average determined using other methods at the same level of
accuracy.
