ИСТИНА

Highlights from two HERA experiments, H1 and ZEUS, on the measurements of jet cross sections and the hadronic final state in electroweak $e\pm p$ collisions are reviewed. The data were taken since 1992 till 2007, at proton beam energies of 920, 820, 575 and 460 GeV and an electron beam energy of 27.5 GeV. These are measurements of inclusive multijet production as well as the production of mesons with charm and beauty quarks in photoproduction and deep-inelastic scattering. Perturbative next-to-leading-order QCD predictions are compared to the measurements. (*) In memory of two outstanding personalities Nikolay Zotov and Pavel Ermolov.