Aula Conversi, Roma 1

Shower Montecarlos are the most heavily used "theoretical" tools for high energy physics. They are based upon the resummation of an infinite class of dominant QCD graphs, integrated by some phenomenological model of hadron formation and by all what is known about decay and branching ratios of particles. In this talk (meant for a general audience) I will give an elementary overview of how they work, and present some new developements and ideas for improvements by inclusion of higher order QCD effects in the hard processes.