XML--What Is it and Why Should We Use it? XML (eXtensible Markup Language) is touted by some as the really big innovation that's going to be most helpful to Web developers in the near future. In fact, two recent speakers who addressed the Dallas/Ft. Worth chapter of the Society for Technical Communication made a point of telling us that we needed to get busy and learn XML. I'm not sure why, but since knowledgeable folks are touting it, I'm going to make it very easy for my readers to find the skinny on this XML thing and judge for themselves whether it merits their time and attention. First, you probably want a definition of XML. Here's one from PC Webopaedia XML: Short for eXtensible Markup Language, a new specification being developed by the W3C. XML is a pared-down version of SGML, designed especially for Web documents. It enables designers to create their own customized tags to provide functionality not available with HTML. For example, XML supports links that point to multiple documents, as opposed to HTML links, which can reference just one destination each. Whether XML eventually supplants HTML as the standard Web formatting specification depends a lot on whether it is supported by future Web browsers. So far, the only major browser vendor to endorse XML is Microsoft, which has stated that XML will be supported in a future version of Internet Explorer. ED NOTE: I understand that Internet Explorer 4.0 is XML-enabled and that XML capabilities will be included in Netscape 5.0. Well, we now know just enough to realize we don't have a clue as to what XML is all about. So... The truth--the whole truth, etc., about XML Probably the best way for you to find answers to your burning questions about XML is an excellent article, " 20 Questions on XML," on the BUILDER.COM site, dated 3/10/98. Among other things, the author says: "...XML will have a life outside of the Internet, serving the publishing industry at large, for example, and especially people who produce documents intended to appear across multiple media. Some large-scale document publishers who have been using Standard Generalized Markup Language (SGML) for years will convert to XML. Still, platform-independent XML was developed for the Web, and that's where it will have the most impact." For a more recent report on the the progress of XML as a Web tool, check out the ZDNet site for Jesse Berst's comments dated June 23, 1999. And you can use XML.Com as a current resource on the subject of XML. Who should learn XML? In answer to the question, Who Should Learn XML? The "20 Questions" author says, "All Web builders need to know enough about XML to decide whether or not they should use it. E-commerce sites and sites that manage large numbers of documents stored in databases are obvious initial candidates. Managers who might not need to learn XML syntax or how to create a DTD will still want to understand XML's potential in order to make use of it. "HTML is still more than adequate for marking up information if the ultimate goal is simply for it to be read by a human being. But if you want to prepare for automatic processing of data, you should think about incorporating XML into your publishing systems." How easy is XML to learn and use? Here's the opinion of one L.C. Reece in an article titled "XML is simple. When looking at XML the average user may find that hard to believe. Compared to HTML it's not. Compared to SGML it's a study in simplicity. SGML's specification is 300 pages. XML's 33. Overhead devoted to obscure thought management has been torn out in favor of essentials. XML gets to the point. "XML carries well. It's reason for existence is Power + Portability. SGML has power. HTML has portability. XML has both. XML can be browsed with or without its DTD, making it download faster. All a browser needs to view XML is the thought itself and the stylesheet controlling its look. If stricter validation is needed, its DTD can accompany it and provide exacting details of its markup." ED NOTE: The links to "stylesheet" and "DTD" definitions were supplied by Aunt Mary. What he doesn't mention is that in addition to stylesheets and DTD, you must learn learn something about DHTML, and you may have to learn about CDF, OSD, and RDF--ingredients necessary to implement XML coding on the Web. If you get into e-commerce, you'll likely get involved with CBL, EDI, PIX, OBI, and OTP. Excuse me a moment; I'm gagging on the alphabet soup! How can you learn XML? Following are some sites that offer tutorials in XML: ZDNet's "An Introduction to XML" Microsoft's "XML Tutorial"