Often the term is glossed over in the interest ofáákeeping the non-technical audience awake, so for many people it is justácategorised as one of those computer languages that make the internet work. But what makes Extensible Markup Language (XML) such a big deal, and how is it different from the plain old hypertext markup language (HTML) we read in our browsers every day?
HTML and XML are both markup languages, which means they describe information in a way that allows programs to know what to do with that information. In HTML, for example, the markup tags are included in angular brackets. So bold will tell a browser to display that word in bold type. HTML, though, has a defined number of tags that can be used, whereas XML has no limits. It's aámetalanguageá- a language for describing other languagesá- which lets you design your own markup tags. This allows much more complex structuring and description of information, and it also allows XML to be the basis for other languages. WAP, for mobile internet browsing, is based on XML.
The biggest advantage of XML in the area of e-commerce is that it can easily be used to exchange data between incompatible systems. In this respect it has been hailed as the replacement for electronic data interchange (EDI) which, although useful for many larger companies in the past, has failed to deliver business value to smaller companies.
Although the first specifications for XML were published by the World Wide Web Consortium (W3C) in 1997, it is still very much a work in progress. These specifications spelt out the syntax, or grammar rules, for the language, but this was just the foundation for a lot more work. The programming community is notoriously competitive, and while this competition helps push the boundaries of what is possible, it also results in a rather chaotic collection of revised specifications, working drafts and recommendations on different aspects of applying the language for practical purposes.
Last November the United Nations (UN) got involved, and for once it wasnÆt to break up warring factions. Well, not entirely. The UN body for Trade Facilitation and Electronic Business (UN/CEFACT) and Organization for the Advancement of Structured Information Standards (OASIS), an IT industry consortium, joined forces to initiate a worldwide project to create Electronic Business XML (ebXML) û aástandard that will make XML data understandable across industries and international boundaries. The end result of collaboration among the worldÆs leading companies and independent experts will, they hope, be the bringing together of all the disparate XML bits and pieces into a global framework thatárealises the promise of todayÆs much hyped e-business revolution.
For those wondering why the UN is getting involved inástandardising computer languages, itÆs worth mentioning that UN/CEFACT was also responsible for developing and promoting the international standard for EDI, the pre-internet data sharing infrastructure thatáebXML promises to replace and enhance.
TheáebXML organization has set itself an 18-month deadline to complete the comprehensive specifications and at its fourth week-long meeting last month its various working groups pushed ahead with the technical stuff, although some observers have expressed doubt about them meeting their deadline of May 2001. The main problem? Getting everyone to agree.
There was good news before the meeting though, with the Global Commerce Initiative (GCI), announcing that it would base its technical infrastructure on ebXML. GCI, formed in October 1999, is a group ofáinternational manufacturers, retailers and standards bodies. It includes such household names as Johnson & Johnson, NestlT, Kraft Foods and Marksá& Spencer.á
But even if the teething problems are sorted out andáebXML continues to be adopted as a global standard, experts warn that it will still have limitations, just like any technology. And while it might be the best solution for businesses today (or next year), new and improved standards will emerge further down the track.
A response taken from the frequently asked questions (FAQ) page at xml.com puts this into perspective nicely: ôMany people's expectations are too high, not just for XML but for any heavily-marketed technologyádu jour. If your boss has read that XML (or whatever) will cure world hunger, it will do you no good to know otherwise. And, needless to say, the world's hungry will be just as underfed as ever.ö