the research of powerful problem solving environments (PSEs) is strongly motivated by the increasing diversity in scientific and engineering computation. in this paper, the first design of lupin, a layered framework of PSEs constructions based on the web is proposed and discussed. the idea of invoking web technologies such as XML and the emerging web services for lupin's approach; the conception of mathematical web services and the implementation of lupin based on the conception are briefly considered. A proof-of concept system addressed by the combination of the current web service protocols, mathM, computer algebra systems (CASs), interactive math and the relevant XML technologies is also presented to check out the feasibility and disadvantages.