What is about Web services that is driving its popularity and adoption ? First, and perhaps most important, Web services are based on widely accepted industry standards (many of which are XML-based). In this way, the Web services model is fundamentally different from previous distributed computing models such as the Common Object Request Broker Architecture (CORBA) standard and Microsoft’s Compound Object Model (COM) programming, which each essentially required that users on both ends of a distributed system run the same programs. Web services, in contrast, have no such requirements and are better suited for connecting heterogeneous systems. This means, quite simply, that Web services are well equipped to solve some of the most perplexing and expensive technology issues confronting businesses today. David Smith, vice president and research fellow at Gartner (an American research institution) said that “Enterprises that haven’t acquired Web services experience by 2009 could find themselves at a competitive disadvantage”. Furthermore, IDC estimates the Web services market by 2007 at US$21 billion.