by David G Propson
Just when you’ve got all this new economy jargon down, they throw new ones at you. XML? Isn’t that the new football league being started by the World Wrestling Federation? The one with Dick Butkus as a head coach? Nope — that’s the XFL. In fact, XML stands for eXstensible Markup Language, a kind of beefed up version of our old friend HTML — or Hyper Text Markup Language (see “Afraid to Ask,” April 1999) — a Refrigerator Perry to its Walter Payton.
XML was cooked up several years ago when that particular letter was on every one’s lips — especially those techies in the generation named after it — but it’s just now beginning to find popular and useful applications.
IS “EXTENSIBLE” REALLY A WORD?
Webster’s Ninth traces the etymology of “extensible” back to 1611, but what it means 400 years later is that you can take some concepts familiar from HTML and then create your own specialized system of marking up documents.
For instance, Web designers want to create documents that can be hyperlinked to other documents, so they use tags like <a> before and after a given word to make the browsers understand that what’s in between is a hyperlink. Or if it simply needs to be emphasized put a <B> for bold or an <I> for italic before and after.
But let’s say you want the browser (or some other piece of software) to recognize a piece of data as denoting the size, weight, or price of an item. XML lets you create custom tags, so that you could place <SIZE>, <WEIGHT>, or <PRICE> around each entry, and the program that read the document would know exactly what that meant and what to do with the data.
This means businesses that need to exchange data electronically — which these days is practically everybody — may now have a much greater ability to do so. To stick with the football metaphors, this is the equivalent of the invention of the forward pass.
WHAT, EXACTLY, DOES IT DO?
Most companies that start seeing the benefits of XML at first won’t even notice it. It will be used in software or on the back end by services they sign up with.
For instance, some wireless services use an HTML-like language called Wireless Markup Language to format their pages for viewing on small PDA screens and even-smaller mobile phone displays. Because XML was used to create the tags WML employs, WML is wonkily referred to as an XML-defined language. In the future, XML could be used for everything from creating a single, universally accessible file format for graphics to printing out sections of books and documentation a la carte.
But by far the biggest benefit for most businesses will come in exchanging data with companies that use different software or systems. XML can be used to create a standard format that all systems can share, and each company’s information can easily be translated from their internal file format to the XML-defined standard.
If you think this is beginning to sound a lot like EDI (which I wrote about in this column last month), you’re not alone. XML will most likely be the key to Internet-enabling of many industries’ supply chains and business-to-business exchanges. When that much-prophesied moment arrives at last, and you really can buy and sell everything you need online and share all your important data electronically, it’s likely XML will be the tool that took you there.
X MARKS THE SPOT
Here are a few places to go for more information on XML and associated technologies.
* the world wide web consortium’s XML page
* the XML industry portal
The Electronic Business XML Consortium is dedicated to creating a framework to allow exchange of data among companies and across industries.