Coming to Terms with Extensible Markup
By Michael Floyd
My Uncle Clayton is, by any standard, an old-world programmer. His pony tail, now more white than gray, hangs dangerously close to his belt line. His favorite T-shirt, a faded, double-X, Grateful Dead vintage, is now too short to tuck in over his belly. His claim to fame is that he programmed on the world's first PC, the Altair, by setting switches to represent bit values. His favorite programming language is still, of course, Assembly Language.
Uncle Clayton and I have a great rapport, but when it comes to XML, he makes no bones. "XML?" he asks bluntly, "you might as well call it seXML." He's referring to all of the hype, so I quip back: "Well, if your name is Joe Homepage, you probably don't care much about XML." Indeed, if you're part of a Web-design shop that, for a nominal fee, will set up a "Web presence" for the small business owner, you probably don't need to care. XML benefits applications of a larger scale and purpose.
Unrelenting, Uncle Clayton jabs back. "My boy, XML is just a fad. It's time you get over it." Of course, Uncle Clayton knows that XML lets you separate data from presentation and business logic. That leads to all kinds of benefits, not the least of which is device independence. By using XML to mark up my data, I can publish it once on my Web site, and transform it to any other language I choose. I can output HTML that's customized for display in Netscape Navigator 4, or I can generate Cascading Style Sheets (CSS) that can display the same data differently in Internet Explorer 5. In fact, my data can be displayed on a wireless device, or even rendered in WebTV.
