Microsoft Corp says it’s seen the light and is abandoning the remote procedure call underpinnings to the COM+ component object model in favor of a message passing approach based on XML. It says that by exposing object services as XML, developers can use them through their existing skill-sets, and data interoperability with other systems will be opened up. The messaging paradigm is the way for scalable, de-centralized autonomous systems that are open and internet friendly said Microsoft’s Paul Maritz, group VP of Microsoft developer relations. He said that Microsoft wants to establish a set of loosely-coupled, message-oriented web services not limited to a single programming model or language.
The old sea of object vision is not going to happen, said Maritz, taking a swipe at Sun’s Jini, which is based on remote method invocation, and also at the Object Management Group’s now somewhat elderly Corba services. Maritz admitted that Microsoft’s own DCom technology fits into the same category. Jini, he said, required one language, one runtime, and a closed communications method whereby all the machines participating need to have the right runtimes – in the same versions – to work together.
We’re doing deep replumbing of COM so that objects interact via XML, said Maritz, others have used an XML parser and a standard schemas to deal with the messages – we’re making that native. Microsoft is working on additional protocols in XML tags to provide additional information, such as timing, error handling and security, he said. For some time, Microsoft has been developing support for XML-based RPC through SOAP – The Simple Object Access Protocol – now on version 0.9. SOAP defines a simple, extensible message format in standard XML, providing a way to send XML messages over HTTP. It is currently soliciting industry feedback over the specification. UserLand Software Inc, and DevelopMentor Inc are co-developers. The spec was released on Monday, and can be found at http://www.xmlrpc.com.
Key to the project is XML support within Visual Studio, implementing a web services programming model. Both the Visual Basic and Visual C++ tools will support XML so that programmers can access XML direct from their code, and Microsoft says it is working on the integration with ten other commercial and academic programming languages as well. The first to add support will be Visual Basic in Visual Studio 7, due out next year. XML will become a core part of Visual Basic, said Maritz. á
