Selected HERMES results on semi-inclusive meson production

The HERMES experiment at DESY in Hamburg collected semi-inclusive deep-inelastic scattering data using the 27.6 GeV HERA lepton beam and various gaseous light and nuclear targets. Results of charge-separated hadron-identified multiplicities and multiplicity ratios, measured on light and heavier targets, are shown as well as azimuthal momentsmeasured fromunpolarized hydrogen and deuteriumtargets. Furthermore, Sivers and Collins amplitudes, extracted from measurements on a transversely polarized hydrogen target, are presented.