XML promises to transform government's use of the Web

Government information managers and commercial application developers alike are buzzing
about the Extensible Markup Language, which tags nontext Web content for easier searching
and delivery.

“This is one of the rare technologies that all the big players, who tend to
disagree on most everything else, are in favor of,” said Charles F. Goldfarb, the
Standard Generalized Markup Language’s chief inventor. “XML is mass-market
SGML.”

Goldfarb said he thinks XML will fundamentally change the ponderous nature of data
processing and storage. “The vast majority of XML documents are going to be generated
instantly from databases, read by other programs and then destroyed,” he said.

In XML, Microsoft Corp. and other industry leaders see the potential for transforming
the way Web content is distributed. Government software developers like it for different
reasons.

Engineers at NASA’s Goddard Space Flight Center in Greenbelt, Md., plan to use XML
to develop an instrument control language for infrared devices on satellites and space
telescopes.

“It’s a little different from what XML is normally used for,” said Troy
Ames, a computer engineer in Goddard’s Advanced Architectures and Automation Branch.

NASA engineers will use XML syntax to describe classes of infrared instruments, control
procedures, communications protocols and user documentation. Computers will parse the
tagged data and generate instrument control code, most likely in Java, Ames said.

At the moment, the engineers are still trying to pick their XML tools. “There are
so many new ones coming out every day that we haven’t committed to writing any tools
ourselves yet,” Ames said.

As a format for data exchange, XML can package objects from multiple data sources, and
XML-aware applications would be able to read the enclosed data.

“Millions of Excel programmers want to pull data into their spreadsheets”
from mainframe and Web server sources, Goldfarb said. XML might become a universal
translator, he said.

Unlike the Hypertext Markup Language, which has a built-in presentation style, XML is
flexible.

It can pull data from databases, merge it with different style sheets and display it on
everything from a large-screen computer to a small-screen pager.

SGML, which was developed for tagging and publishing large documents, “filled a
need for the government that couldn’t be fulfilled anywhere else and still can’t
be,” said Goldfarb, who has published books about XML and SGML. Later HTML, a subset
of SGML, “came along and created this huge application of SGML for online
short-document publishing,” he said.

But far more useful than HTML’s text description, Goldfarb said, is the way XML
and SGML can describe nested object structures and properties.

“Object databases are great for rich hierarchies, which is exactly what XML
is,” said Mike Hogan, vice president of business development for Poet Software Corp.
of San Mateo, Calif.

Hogan said he sees XML as the killer app that could create a mass market for
object-oriented databases, which so far have succeeded only in niches such as network
management and process control.

About two years ago, Poet Software discovered another niche market for its object
database—SGML publishing. A year later, as XML started to create a buzz, Poet
Software began tuning its Poet Object Server database to store XML objects.

“XML will do for object databases what tabular data did for relational databases,
only in Web time,” predicted Dirk Bartels, president and chief executive of Poet
Software.

Bartels said he wants to make Poet Object Server the object repository for all kinds of
XML, HTML and SGML applications. The object database server supports the Object Data
Management Group’s application programming interface.

The company’s Poet Content Management Suite, built on top of Poet Object Server
5.0, has revision control, check-in and check-out capabilities, full-text indexing and
workgroup collaboration support.

But Hogan said XML cannot reach its potential in electronic commerce, electronic data
interchange, data reuse, improved search engines, push technology and interactive
electronic publishing until there is an adequate base of XML-tagged data on the Web for
such applications to tap.

The first step, he said, will be building a critical mass of XML-tagged Web data.
Leading database vendors such as Oracle Corp., IBM Corp. and Microsoft are designing ways
to return XML-tagged data in response to Structured Query Language queries.

Microsoft’s Internet Explorer browser supports XML minimally, and Internet
Explorer 5.0 will do much better XML parsing, Hogan said. The next release of Netscape
Communicator will support XML, too.

For XML information, visit http://wdvl.internet.com/Authoring/Languages/XML.