2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/41116I discuss the current status of the comparison between theoretical predictions and experimental data, relevant to the production of open charm and bottom quarks in photon-hadron and photon-photon collisions. I advocate the use of a formalism that matches fixed-order computations to resummed computations in order to make firm statements on heavy flavour production as described by perturbative QCD.10 pages Latex; 7 figures included. Talk given at EPS01, 12 - 18 July 2001, Budapest, HungaryHigh Energy Physics - Phenomenologytext