If XML lives up to the hype, soon we'll all be interacting with XML applications, which will make it vastly easier to conduct commerce, download software and find content on the Web. It's a big promise, but XML â" even if it is still being defined in standards bodies â" looks like it's up to the task and every major Web vendor is rallying behind it.
What is XML (besides yet another new acronym) and why do you as a marketer and builder of Web sites need to know about it? Let's start with some background.
The basic language of today's Web is HyperText Markup Language (HTML), which consists of a series of tags and notations for building basic Web pages. HTML was designed specifically for the Web and is designed for the building of simple, mostly text-graphics-and-links Web pages.
HTML itself is derived from the Standard Generalized Markup Language (SGML), a much more powerful language that has been used for years by industries and government to help create and manage documents.
Splitting the difference
XML splits the difference between HTML and SGML. Like HTML, it is simple and lightweight and built for delivery over the Web. But also like SGML (from which it, too, is derived), XML is much more powerful and includes the ability for individual companies or industries to extend it with new capabilities and tags suited to their needs. That's why they call it Extensible.
However, while you'll hear a lot about XML, you won't be dealing with XML itself, per se. XML is a tool for creating new Web languages, and already there are a variety of languages that are being built with XML.
For instance, Microsoft Corp. has used XML to build the Channel Definition Format (CDF), which it is proposing as a universal way to describe push channels. Netscape Communications Corp., in turn, is forwarding an XML version of its MetaContent Format (MCF) that will compete with CDF.
Separately, Microsoft and Marimba have proposed the Open Software Description (OSD) language as an XML-based way to deliver updated software applications over the Web.
In addition, industries can use XML to build languages to serve their specific needs. The industry group CommerceNet is working on XML-based languages to fuel electronic commerce applications and other industries, such as the auto and chemical industries, are working with XML as well.
End of HTML?
Will XML spell the end of the Web and HTML? No. Instead, think about it this way: Every builder needs the right tool for the job. If you want to build a mainly text-graphics-links online environment like the Web today, HTML is a perfect fit.
But if you want to build a new Web that is driven by transactions, is personalized in nature and is more easily navigated by things like search engines and intelligent agents, then XML and XML-based languages are the way to go.
Will this change the do-it-yourself, low-barrier-to-entry nature of the Web? Well yes and no. First of all, while most anyone can write an HTML page, few do it well. So the Web â" especially for serious busines-ses â" is no longer a hobby or sideline effort anyway.
And while the average person won't write their own XML-based language, there will be lots of tools that make it easy for users to take advantage of XML technology. For instance, already there are drag-and-drop tools for building CDF push channels.
In the end, XML works behind the scenes to make the Web a more commerce- and business-ready environment, while keeping things easy for users.
When will XML arrive? Well some applications like CDF are here already even as the World Wide Web Consortium puts the final touches on the XML specification. The battle now will be to see how vendors like Netscape, Microsoft and others compete to own XML the way they battle for top spot on the Web today.
And the larger challenge will be to see how quickly businesses can learn about and adapt to the new, more powerful and flexible Web that XML will help to create.
Richard Karpinski is editor at large for Internet Week and author of "Beyond HTML" from publisher Osborne/McGraw-Hill.