XML is the latest buzzword in e-business technology. Danny Bradbury
explains how it is set to make Web data smart enough for
business
What is XML? XML stands for eXtensible Markup Language.
It developed as a subset of the Standard Generalised Markup
Language (SGML). It has gained prevalence in the last 18 months
thanks to companies like IBM, which have pushed it as a
standard.
Why is it important? On its own, XML is pretty much
useless to the average IT department. This is because XML is as
wide as data itself, and is too nebulous to be useful. Instead, the
importance of XML is as a language for defining other Web
languages. In HTML you can use specific tags to give instructions
about the way that a Web page will look. With XML, you can define
your own tags that enable your software to tell other pieces of
software what a particular piece of data means, and what should be
done with it.
This makes it particularly relevant in a business-to-business
e-commerce context, because companies can use XML-based messages to
send messages to other firms' computers that are particularly
relevant to their business. An XML language is defined in something
called a Document Type Definition (DTD). DTDs are under development
for many different vertical markets, and the types of tags used
for, say, a DTD in the shipping and distribution industry will
differ from those in a DTD for the legal profession, or for the
medical world, for example.
XML messages can also be used to send data about their own tags,
so that an XML-savvy application at the receiving end can read the
message and understand what is to be done with the data, even if it
has little information about the contents of the message
beforehand. What this means in practice is that you can code both
processes and data into an XML message, to a certain extent.
However, do this with care, as you could find yourself putting a
big communications overhead on top of your application data.
Who looks after standards issues? The World Wide Web
consortium (W3C) has standardised XML as a language for use on the
Internet.
How does Microsoft's Biztalk fit in? The first thing to
remember is that you don't need Biztalk to make XML work. Microsoft
developed its Biztalk server (which is still not shipping and is
very late) as a means of exchanging e-commerce information between
servers. The independent Biztalk movement has been set up to define
XML-based schemas for vertical market applications, but there are
many other schemas.
How many people are using it? Few people are actually
using XML in anger because it is such a new technology. The main
drive, as always, has come from the supplier community, where
companies are using it as the latest buzzword to increase sales.
The truth is that, as always, the customer community will be a
couple of years behind, and you're unlikely to see it being used in
force until 2002-3.
The main impetus behind XML is as an integration language, and
so a lot of enterprise resource planning suppliers have announced
support for it, as have the enterprise application integration
suppliers - those companies selling "hub" software to take data
from various applications and translate them for other applications
to read. Expect to see significant amounts of activity in the
electronic procurement area.
Is it the only answer for e-business? Certainly not, in
spite of what some suppliers may tell you. In fact, right now it's
probably not the best route to take because it is still relatively
immature. There are other solutions for business-to-business
e-commerce, such as the increasing number of online
business-to-business marketplaces. Check out places like
CommerceOne and Ariba for more information on these. Some of these
marketplaces are offering XML support, but not all of them require
you to use XML.
Where can I find out more information? Check out
www.XML.org for information about what's going on in the XML world.
You can also try www.biztalk.org for details about the ongoing
Biztalk developments. And don't forget www.w3c.org for the latest
on XML standardisation.
What are the staffing issues? At present, there are few
people with a clear enough idea of XML and how to use it. Much
e-business software offers XML support, but it's unlikely to be a
plug-and-play operation. If you go down this route, you need
someone to take your e-business application and map it onto an XML
schema for you, which could be tricky. If you can find someone
competent enough to do this for you - and that's a big if - then
you'll probably be paying through the nose.
BASDA and XML
Many groups have been working to create specific vertical market
DTDs and schemas that work with XML, but the Business and
Accounting Software Developer's Association (BASDA) has taken a
different approach. Last summer, it announced a set of schemas
designed for more horizontal XML-related communications between
accountancy software packages, under the umbrella name eBis-XML.
Over 50 different software suppliers have agreed to support the
schema. In December, the organisation published the first versions
of its Order and Invoice Specification. Dennis Keeling, head of the
association, says that more specifications will complement the
schema at a later date.
Additional Standards associated with XML
The W3C has been working on other standards that are related to
XML, some of which are complete and some that still need to be
ratified. These standards will help developers to make their XML
programs and documents more functional, and they include:
XML-Dsig - a standard for providing digital signatures
that can be used to verify XML documents.
Extensible Stylesheet Language (XSL) - This is a language
for designing stylesheets within XML that can be used to define the
presentation of lots of XML documents at once.
Resource Description Framework (RDF) - This standard
describes how XML can be used to link information about lots of
different Web resources together. Such resources can include site
maps, content ratings and search engine data collection.
XML Linking Language (Xlink) - this allows elements to be
inserted into XML documents that link the documents together.
XML Base - Lets developers define a base URL within an
XML document that is always the same regardless of other URLs. It
will be used in conjunction with XLink.
XML Query - Defines terms that can be used to query XML
documents.