XML holds out the promise of a universal and standard means of object/component communication that vastly reduces the need for reliance on competing ORB standards such as Enterprise JavaBeans, COM, and CORBA. In this book, Don Box covers every key issue, technology, and technique involved in using XML as the "ultimate translator" between disparate software components and environments. Essential XML starts by contrasting the XML approach to software interoperability with pre-XML practices, technologies, and methodologies, including COM, CORBA, and EJB. Next, it examines XML-based approaches to metadata, declarative and procedural programming through transformation, and programmatic interfaces -- showing how XML's platform, language and vendor independence -- and its accessibility -- make it a far more effective solution for software interoperability than any alternative. The book also contains detailed coverage of the Simple Object Access Protocol (SOAP), an XML/HTTP-based protocol for accessing services, objects and servers in a platform-independent manner.