New object-oriented technologies have been conceived and implemented over the past decade in order to manage complexity inherent in information systems development. Research has spanned from information systems modelling languages (UML and OML) to databases (ODMG), from programming languages (Java) to middleware technology (CORBA). A more widespread use of the Internet has led to the emergence and integration of various other technologies, such as XML and database connectivity tools, allowing businesses to access and exchange information over the Internet. The main theme of OOIS 2000 was "Object-Technology and New Business Opportunities" and focused on research conducted in the area of effective information systems development for the promotion of e-commerce. Papers were invited from academics and practitioners. The thirty-nine papers accepted for oms 2000 are included in these proceedings. It is nice to see this year that the shift from centralised to distributed systems and the widespread access and use of the Internet has allowed the advent of new opportunities for businesses to exploit, in the form of e-commerce.