XML:The good, the bad, the real

How do you get information in disparate applications to work with each other? Can the eXtensible Markup Language (XML) be used to create an integration environment? Is XML right for your organization? The answer to the last two questions is both "Yes" and "It depends."

"XML is being driven by business people who need to interchange information as easily as possible," said Scott Hebner, director of e-business technology marketing at IBM. Yet XML cannot do anything by itself. There must exist a process that acts upon it; there must also be some way to parse the data and then apply it. What is key is the application of the information, and there are a number of ways this can be handled.

Custom development -- One method of applying data is to create your own apps that will process XML data using languages like C++ or Java, or scripting languages like the Tool Command Language (Tcl). Text-based scripting languages, such as Tcl, offer an opportunity to use XML. They also have a relatively low learning curve.

"We think [XML's] primary early usage is integration of data between enterprises. All the integration stuff is outside of XML, [and] that's where scripting comes in," said John Ousterhout, discussing how he felt XML and scripting could be used together. Ousterhout is the creator of the Tcl scripting language and CEO of Scriptics Corp., Palo Alto, Calif. He believes that the biggest advantages of scripting are its ease of development and ease of integration.

"Scripting languages are ideal for making existing applications, devices and protocols work together," he said. "You build new applications out of existing things, rather than starting from scratch." Tcl also offers extensions to all the major databases and operating systems, making it what Ousterhout would call a viable integration tool.But because scripts are interpreted and not compiled languages like C++ and Java, performance can be a factor. While Ousterhout recognizes the difference, he makes the point that performance rarely matters for integration applications because most of the execution time is spent inside the components being integrated.

XML toolsets -- Another way to apply the information parsed in XML documents is to purchase tools that handle the mapping for you. Vendors such as Oracle Corp., Redwood Shores, Calif., and Bluestone Software Inc., Mt. Laurel, N.J., are racing to meet this need. Oracle has released XML SQL Utilities and XSQL Servlet, which facilitate the reading and writing of XML information to and from Oracle databases.

Bluestone has released a variety of products geared toward the integration of XML information. Bluestone XML-Server is a dynamic XML server that processes and prepares XML documents on the fly. For example, a purchase order in the form of an XML document is received, parsed and then processed into the local database. A receipt request document is then prepared in XML and sent to the appropriate location.

Bluestone Visual-XML is a developer's toolkit that helps companies build XML-based applications. According to Bluestone, users will be able to automatically generate their DTDs and XML documents through graphical drag-and-drop programming that generates pure Java and pure XML code.

Not to be outdone, Scriptics has released its own application server. The company's E-Business Server is said to provide a platform for creating business-to-business applications based on XML with built-in support for databases, COM and Java. Additionally, development opportunities exist with the use of the Tcl scripting language.

What does it all mean?

A variety of factors must be addressed before an organization embraces the XML standard as a means of integration. Can your company absorb the increased costs required to implement the change? How loosely are applications coupled? Are you willing to accept the risk of adopting one of the related XML technologies (XSL, XQL, XPointer, XLink) before it is finalized?

According to GartnerGroup, a Stamford, Conn.-based research firm, IT project costs will increase because of the expenses associated with XML education, the consulting required to develop in-house XML engineering skills, and the costs associated with acquiring and deploying new XML-based technology. However, Gartner estimates that the return on investment will be an IT infrastructure that more easily accommodates new users, applications and business partners.

In terms of the technology itself, XML's value lies in its ability to send information back and forth between loosely coupled applications; for example, in merger and acquisition situations. But questions remain. When will the definitions
of XSL and XQL be finalized? And there is still uncertainty whether XML documents will use DTD or the emerging schema standard to define content.

The bottom line is that XML is not the answer. Rather, it is part of the answer. If you need to share information with many disparate applications that exist outside the enterprise, then XML is a good solution to use. If your applications are inside the enterprise -- and if you still retain control over all aspects of application maintenance -- you might want to handle integration needs in-house and wait until the dust settles.

In either case, you might want to follow the lead of most of the Fortune 500. According to GartnerGroup, 75% of Fortune 500 companies are prototyping at least one XML app by year-end 2000. In this way, you too can come to an intelligent decision regarding the cost and benefits of XML for your firm.

About the Author

Dan Hargrove is a technical architect at Akili Systems, a provider of custom e-solutions.