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XML: XML to ease Net tensions

MAY 1998

Middleware role to simplify inter-object communication

The Extensible Markup Language (XML) protocol may ease the pain of the distributed computing war on the Internet by emerging as an independent middleware standard.

Microsoft is expected to announce in three weeks plans to use XML as a link for communication between the Component Object Model (COM) and CORBA.

"XML will become important across a broad range of protocols, including COM and CORBA," said Adam Denning, group program manager for XML technologies at Microsoft. "You could definitely use XML as a way of bridging protocols."

Sources close to the company said that is exactly what Microsoft plans to do. However, Microsoft officials declined to provide details.

Other companies are also moving in that direction. DataChannel this week will follow a similar strategy, delivering a Java-based tool that passes COM Document Type Definitions (DTDs) written in XML across the Web using HTTP, essentially enabling Java-capable systems to talk to Windows boxes.

David Pool, DataChannel chief executive officer, said HTTP and XML provide a proven, scalable architecture for Web-based distributed computing.

"This is a logical extension to all computing platforms, including Windows. We just did it in Java," Pool said.

DataChannel's WebBroker technology uses a Java servlet as an object request broker combined with an XML parser to format the request into a COM DTD. The XML-based method calls and method returns are both transported using HTTP, and a Java applet on the client converts and processes the request.

For example, a company that wants to run applications via the Web can simply extend its HTTP Web server with WebBroker and not have to open firewalls to Distributed COM (DCOM) or the Internet Inter-ORB Protocol.

DataChannel last week said it plans to submit its DTD schema to the World Wide Web Consortium as a standard way to handle distributed computing across XML.

Pool said the combination of XML and HTTP is a more robust way to achieve cross-platform computing than the method Java offers.

XML timetable

The technologies that make up the Extensible Markup Language (XML) are in various states of the W3C standards process: XML-Data: This proposal seeks to classify data stored within XML in a more meaningful way, whereby a number would be recognized as a number and not just text, enabling computations. XLL: The Extensible Link Language, now broken down into two components, Xlink and Xpointer, enable XML documents to link to one another in a more dynamic way than typical Web pages. XSL: The Extensible Stylesheet Language, bridges XML data to its display, whether that page is a Web page, multimedia, audio, etc.

XML gets ready for prime time

Although auxiliary pieces of the Extensible Markup Language (XML) technology are still under development, early adopters and developers say XML itself is ready to be used as a data interchange format today.

XML lets developers add rich structure to data in a neutral format that can be used by Web applications, servers, middleware, and end-users.

XML is a standard of the World Wide Web Consortium (W3C), and although some complementary pieces are working their way through the standards body, developers can begin storing data in XML, without fear of it becoming obsolete. This is because the other XML components, namely XSL and XLL are written in XML syntax -- no matter how new the progress, they will be able to use XML data.

"Unlike the old days where round one wasn't perfect, now we can just add the new pieces of our data set," said J.P. Morgenthal, president of NC.Focus, an IT advisory company in Hewlett, N.Y.

Morgenthal also said XML as a whole may seem confusing because it can be used both for Web publishing and for more general data interchange. Many XML-related proposals at the W3C will only affect publishing. Because many XML developers came from the Standard Generalized Markup Language world, of which XML is a simplified derivative, they see it primarily as a publishing prize that isn't ready for prime time yet. But viewing XML only as a publishing format is missing the ball, he said.

"There is enough there now for people to take advantage of it to use for interoperability," Morgenthal said. "If I'm doing data mining or integrating two off-the-shelf applications, I can get an XML parser and access that data set. The point is that the data set is the same between my applications. I can change structure all the time without breaking links to my applications."

Microsoft, which is leading the XML developer charge, agreed that companies can begin today to integrate XML into their existing infrastructure and Web applications.

According to Adam Bosworth, general manager of Weblications at Microsoft, to become XML-ready, companies should learn the XML specification and see what the language can do within their organization. Bosworth said people should begin to get a feel of how to view, edit, and manage XML data. As an example of how to use XML, Bosworth recently demonstrated an auction page on Microsoft's Web site. The XML demo shows how users can interact live with a server and redisplay parts of the Web page without reloading the entire page.

Before worrying about applying XML structure to corporate information, one analyst said companies need to first look at how their organization interacts.

"Make explicit what your internal processes are and then understand that XML is moving forward with the right building blocks," said Rita Knox, vice president and research director at the Gartner Group, in Stamford, Conn.

Once a company understands its processes, Knox said, it can use XML to bring down the costs of data re-entry. For example, a doctor's office could enter patient information such as name, medication, dosage, and then transfer the data set to a pharmacy. Meanwhile, a company that tracks statistics on the flu could use the same data. There is no mechanism for that kind of data sharing in place today, she said.

"There's a fortune lost due to data being re-entered all the time," Knox added.

Before XML can enable this kind of industry interchange, companies must define common XML tag sets.

Good mechanisms for this are industry professional organizations, some users said.

"Although such organizations are not traditionally involved in computer, Internet, and IT issues, they are set up to set standards in a fair and ethical way," said Dave McCorkhill, director of operations at 800-All-News, in Denver. "They could easily set up committees manned by those members of their organizations who are most interested in the Internet."

In one case, this already is happening. Chrysler and Ford have come up with a standard set of tags for the automotive industry that will be finalized this year, according to Dianne Kennedy, president of Illinois-based XMLXperts.

Another important early step for companies, says Dave Pool, CEO of DataChannel, is to ensure that the software vendors they work with are planning to be XML-compliant.

"That's an education process," Pool said. "There's an inversion now; the customer knows more about XML than the suppliers."

Once IT managers learn XML, the next step is to use XML to expose the corporate Web site's shape, services, and data so other servers can interact with it, Bosworth said.

Pool said XML-enabling legacy data is also an important second step. DataChannel has sold its development kit to several database and document management companies to enable this process.

Bosworth's third step is to implement and support XML grammar for filtering and updates as it emerges, and to engineer client-side objects to talk XML to servers.

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