XML:The good, the bad, the real
- By Dan Hargrove
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
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
Dan Hargrove is a technical architect at Akili Systems, a provider of custom e-solutions.