Calculations of hadronic matrix elements using lattice qcd

I give a brief introduction to the scope of lattice QCD calculations in our effort to extract the fundamental parameters of the standard model. This goal is illustrated by two examples. First I discuss the extraction of CKM matrix elements from measurements of form factors for semi-leptonic decays of heavy-light pseudoscalar mesons such as $D\to Ke\nu$. Second, I present the status of results for the kaon $B$ parameter relevant to CP violation. I conclude the talk with a short outline of our experiences with optimizing QCD codes on the CM5.