We are also engaged in phenomenological studies of the physics potential of present and future high energy particle accelerators in performing tests of the Higgs sector of the Standard Model and of its minimal and non-minimal Supersymmetric extensions, by using numeric calculational methods including full event simulation through Monte Carlo techniques, as implemented in theHERWIG program. Such MC programs are crucial tools needed to analyse present and future collider data, bringing the Southampton group in direct contact with the experiments at BNL, FNAL and CERN. These activities are carried out in the framework of the NExT Institute.