2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/43772Substantial progress has been made recently in the formalisms which form the basis of event generators. I discuss some of the ideas involved, emphasizing the role of higher-order QCD corrections and their interplay with parton showers12 pages Latex. Talk given at DIS04, Strbske Pleso, Slovakia, 14-18 April 2004High Energy Physics - Phenomenologytext