XML gathers momentum

Extensible Markup Language has become a pervasive force in applications in which computers share data or interact. To make the language even more useful, standards bodies are churning out specialized versions of XML at a rapid pace.

For example, in February, the Organization for the Advancement of Structured Information Standards (OASIS) released Extensible Access Control Markup Language (XACML), which allows organizations to build their rules for access to systems or information into the open standard. That way, XACML can eliminate the need for multiple access-control policy languages, which many organizations now rely on.

First released by the World Wide Web Consortium in 1998, XML has matured as a versatile language useful in any kind of data sharing, said Steve Holbrook, program director for emerging e-business standards at IBM Corp. What remains to be done is developing specialized versions that apply to specific tasks.

"XML is the choice," said Jonathan Eunice, principal analyst and information technology adviser at Illuminata Inc. in Nashua, N.H. "There are no contenders, and there never will be." Although proprietary formats and homegrown languages have been used, "they're all going to be phased out in favor of XML."

Federal agencies will increasingly turn to the language, especially as the demand for data sharing rises to meet homeland security and other needs, according to consultant Jim Flyzik, chairman of the Homeland Security Task Group at the Information Technology Association of America. "XML is going to be a key technology for making systems interoperate," he said.

The XML Alphabet

Think of XML as an alphabet. Standards bodies — typically consortiums of vendors and users — use the alphabet to make words and sentences. They define data types and construct code to fill a given need. The standards are then available for any vendor to use. Vendors and users can also mold the language to fit their needs.

Open standards ease the headaches involved in integrating systems, such as making disparate applications adhere to an agency's access rules, said Steve Hanna, senior staff engineer at Sun Microsystems Inc. and a member of the OASIS committee that developed XACML. Sun issued its XACML Implementation Feb. 18, with code based on the company's Java programming language.

"We looked at what's out there today, and it's a mess," he said. "Every application has its own policy language, its own policy syntax. If somebody comes to you and says, 'Here's the high-level policy we want to implement,' you have to translate it over and over again, once for each system."

Even in the absence of a standard, though, XML is much more flexible than a proprietary system, according to Bill Wright, president of Computas NA Inc. The company's Metis product is designed to help administrators construct an enterprise architecture by converting data into XML form.

Because no standard exists for enterprise architectures, Computas created its own. When a standard does emerge, he said, XML will make the transition easy.

Vendors, by and large, support open standards because they level the playing field, said Bill Edwards, chief technology officer at Siebel Systems Inc. Buyers are wary of getting locked into one vendor's product line and are more comfortable when the connection points that support multiple applications are based on something every vendor can use, he said.

In 2002, Siebel, Tibco Software Inc., Vitria Technology Inc., webMethods Inc., Microsoft Corp., IBM and SeeBeyond Technology Corp. formed the Universal Application Network to develop XML-based business processes for their customers.

XML "is not a sideline of our business. We have aggressively put resources into this for about two years," Edwards said. "XML is not some research project, not something on the side. It's real."

And it's spreading rapidly, said James Martin, senior engineering specialist with the Aerospace Corp., which is helping the National Oceanic and Atmospheric Administration construct an architecture to track its inventory of weather sensor equipment.

"There's hardly a tool out there that doesn't [support] XML," he said. "A year ago, I never heard of it."

Government has "a greater need for XML, what it can do for them, than most other sectors," IBM's Holbrook said. "But there's a need to have something that's well-proven, so there's a little more skepticism, I think. The government is a little more laggard in its willingness to jump on emerging technology, but it's been five years now since XML came out."

Word is beginning to spread. The Bush administration's E-Government Strategy, published last year, specifies the use of XML in some of the initiatives. In December, the Navy released an XML policy to coordinate its efforts to adopt the language. The Air Force began using XML-based electronic forms last year, and the Internal Revenue Service's electronic system for filing tax returns uses the language.

"There are a number of government agencies who are looking down the road and thinking, 'Where is this taking us?'" Wright said. "'Is this a one-shot with this administration? Or is it going to fundamentally change the way we do business?'"

***

XML drives bureau's IT initiatives

At the Treasury Department's Bureau of Printing and Engraving, Chief Information Technology Architect Susan Warshaw used a tool based on Extensible Markup Language to create an enterprise architecture in less than a year.

She chose the language for its flexibility. "I didn't want to be locked into a data structure. I wanted to have my own structure, my own meta model," Warshaw said. "From there, I was able to start at the business layer instead of getting bogged down in the technology layer."

The extensible data structure will enable her to easily update the architecture as new directives come from the Office of Management and Budget and as the agency evolves, she said. The architecture describes the bureau's information technology structure to allow staff members to easily look up information about it. However, Warshaw is less sure that her colleagues in the government are aware of XML's strengths.

"Maybe somebody needs to say we need XML," she said. "I don't think everyone's aware of it. It's very exciting what we've done. I would like to see it catch on."