The article whose abstract follows is available from www.mta.ca/~rrosebru/ or in hard copy by request (pls include postal address). Regards to all, RJ Wood Bob Rosebrugh ------------------------------------------------------------------------ Factorization Systems and Distributive Laws R. Rosebrugh and R. J. Wood This article shows that the distributive laws of Beck in the bicategory of sets and matrices determine strict factorization systems on their composite monads ( = categories). Conversely, it is shown that strict factorization systems on categories give rise to distributive laws. Moreover, these processes are shown to be mutually inverse in a precise sense. Further, an extension of the distributive law concept provides a correspondence with the classical orthogonal factorization systems.