Section: APPLICATION DEVELOPMENT

The XML train is boarding and about to pull out of the station, but many companies aren't quite sure where it is going or how to get on. "A lot of people have been on the wrong track with XML," says John Ousterhout, CEO of Scriptics Corp., a business-integration-tool vendor. "They are thinking of it as document-centric, a structured document that will replace HTML."

As the new year dawns, a more appropriate use of Extensible Markup Language is to facilitate business-to-business interactions over the Web. XML lets companies structure and exchange information without rewriting their existing systems or adding large amounts of heavyweight middleware. "This is the huge business-to-business void," Ousterhout says. "There is this big demand, but nothing is there to fill it except XML."

IT managers understand the usefulness of XML. According to an InformationWeek Research Outlook 2000 study, 45% of the 300 IT executives surveyed said XML is on their planned project lists for 2000. "If we didn't have XML, we'd have to build something like it on our own or try to use some low-level API connections," says Roger Bly, founder of Project.net Inc., a San Diego business-to-business project-management portal. Everything in Project.net can be defined with XML. Project.net participants can exchange information via XML throughout the process of project collaboration and project management.

And the vendor community is listening. Bowstreet International Inc., a business-to-business Internet software and services company, provides XML tools to deliver services over the Web. In this case, the company employs XML within its directory product to describe the business processes that it manages. "Applications can then access these services on the fly," says Bowstreet co-founder Jack Serfass.

Sabre Labs, the applied technology research and development division of Sabre Inc., the Fort Worth, Texas, airline reservations systems company, is using XML despite having a mature electronic data interchange system based on EDIFact, the international EDI standard. "We see XML as a new opportunity, a low barrier-to-entry way to extend our reach," says VP Bob Offutt. Sabre uses Bowstreet's XML-based directory to manage its myriad partners providing travel services.

Despite the enthusiasm, XML is no panacea. "It is merely an enabling technology. XML is nothing by itself," says Philip Russom, director of data warehouse and business intelligence at Hurwitz Group, an IT advisory firm. Instead, Russom thinks of XML as "a small bolt in the E-business machine," albeit a very important bolt.

Like SQL or Java, XML is an enabler of infrastructure technology. While many consider it a language, XML actually is a standard for specifying a document markup language based on plain-text tags. Where HTML tags tell the browser how to display various elements on a Web page, XML tags specify what those elements are.

XML provides the key to separating Web content from presentation. When a system receives a page of HTML content, it can display the page, but it cannot understand what the content means. It can't, for instance, pull price and product data out of a Web catalog page. Using XML and various related standards, systems can parse the arriving XML document to extract some content for processing by other systems while displaying other content in different ways for different viewers.

For example, solutions provider Synergistics Inc. furnishes a knowledge-management product, Prevail Knowledge Center, that includes a portal. At the portal, information that is pulled from a variety of sources must be personalized for each visitor. The company uses XML to separate data and presents only the appropriate subset of the data for a given visitor.

At this early stage in XML's development, the industry is trying to figure out what the technology will do best. Already, XML appears to offer its biggest payoff in three major areas, says Hurwitz Group's Russom: high-end custom publishing; intra-enterprise application-to-application integration; and business-to-business information exchange.

High-end publishing refers to the kind of complex documentation aerospace manufacturers typically produce to accompany major products. While the core products may be the same, each customer's order is modified to meet its unique requirements.

Intra-enterprise application integration refers to the process of integrating two applications within the organization, such as enterprise resource planning with customer-management systems. In the past, companies have spent considerable effort to forge custom integration or, more recently, have purchased application-integration solutions. Both approaches are labor-intensive and costly and have proven difficult to maintain.

But most of what companies want from application integration is data integration. For example, they want certain data from their ERP system to be passed to the customer-management system. Businesses use XML to describe a variety of data types and give them semantic meaning.

NuSkin Enterprises Inc., a Provo, Utah, maker of beauty products, is experimenting with XML as a way to integrate its SAP R/3 ERP system with a variety of other applications, moving data with a lot of record formatting. By converting those formats to XML, says NuSkin software engineer Joseph Ruffolo, the company should easily move data between systems that support XML without having to map the record formats to each individual system.

Automotive Rentals Inc., a Mount Laurel, N.J., fleet-management company, also had the problem of exchanging information between multiple systems. Unable to get all its divisions to standardize on the same system, the company is turning to XML to pull data into common fields. Automotive Rentals could have come up with its own common data format, a tedious and labor-intensive effort, but XML was there and was fast and easy, says Bill Kwelty, the company's manager of customer services.

The biggest interest in XML, however, is focused on business-to-business applications. XML provides a standard way to express data in a structured format. More important, it provides a common vocabulary for understanding the data along with the structure.

The common vocabulary is contained in the document type definition, an ASCII file that describes the meaning of the particular XML tags. The document type definition, which describes the fields and their attributes, can accompany the document, allowing it to be read and understood on the fly by any XML-capable system. Companies can create DTDs for themselves, or join together in industry groups to create them for a particular industry.

The emergence of industry-specific DTDs will fuel the adoption of XML in the business-to-business arena. By standardizing on a set of DTDs, trading partners can exchange XML documents and send and receive requests for data quickly and easily.

EDI was supposed to do for business-to-business data exchange what XML seems poised to do. EDI provides a way to exchange information between organizations in a highly structured way for specific purposes.

While EDI sounds good in principle, it has proven very difficult to implement in practice. Industries spent long periods of time just hammering out the EDI formats. The technology requires the use of complex systems and pricey, value-added networks. EDI also entails painstaking mapping from one field to another. If something changes, even something as minor as adding a new digit to a product identifier, everything has to be redone. Although large companies adopted EDI, often forcing their suppliers to go along reluctantly, the majority of businesses ignored EDI.

By contrast, XML is much easier to deploy, which makes it a natural for business-to-business use, says Sabre's Offutt. XML is based on Internet protocols such as HTTP, rather than relying on some value-added network. The tools--text parsers and Web browsers--are widely available, low-cost commodities. And, companies don't have to hire hard-to-find and highly paid EDI specialists. Almost any programmer can become proficient with XML in a matter of hours. As a result, XML can succeed where EDI and EDIFact has struggled, Offutt says. Where it takes a company six months to implement an EDIFact system at a price that can run well into six figures, he says, a comparable XML system can be implemented in days for little additional cost.

Despite its obvious advantages in business-to-business and enterprise application integration, XML isn't a foregone conclusion. As a markup language, XML lacks procedural capabilities. It must be augmented with some sort of processing, whether scripting or programming, to process the XML data once it gets where it is going.

Also, Hurwitz Group's Russom suggests, companies will need a way to query XML data, an XML equivalent to SQL. A standard has been proposed, XQL, but it hasn't been finalized. Meanwhile, Offutt and others want business processes defined in XML. By defining business processes in XML, the accompanying scripting could be simplified, if not eliminated.

As the new decade begins, XML is far better than anything else available. It's already being widely adopted by systems integrators and vendors, who are working XML into many products.

For most IT organizations, however, XML may remain essentially invisible. Instead, business-to-business service providers will simply incorporate XML into their products, portals, and tools. "Companies will be aware of XML and get the benefits of it," says Gerald Lester, a senior consultant at Computerized Processes Unlimited Inc., a provider of XML integration software for the process manufacturing industries. "But they won't have to interact with XML unless they want to."

PHOTO (COLOR): USEFUL TOOL: Project.net participants use XML to exchange project and management information, says Bly. "If we didn't have XML, we'd have to build something like it on our own."

PHOTO (COLOR): BEST TOOL FOR THE JOB: XML is a natural for business-to-business transactions because it's easier to use than electronic data interchange, says Sabre VP Offutt.

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By Alan Radding