[Archive copy mirrored from: http://www8.zdnet.com/macweek/mw_1129/op_dinucci.html, text only]

Click here to WIN a FREE PC!
JULY 23, 1997


XML: A return to traditional standards might save the day

The first public draft of HTML 4.0, posted by the World Wide Web Consortium (W3C) earlier this month, is distinctly underwhelming. When it is finally approved, HTML 4.0 will codify features that are already supported in Netscape Communicator and Microsoft Internet Explorer, such as frames, style sheets and the Object tag. It will also add new features for tables, forms, math layouts and accessibility.

These are solid, important additions, but Web designers can be forgiven for wishing that the W3C had bit off a little more. It's a tough dilemma: Centralized management of HTML by a disinterested standards body is crucial to the Web's development, but the consensus process is painfully slow.

Miraculously, the solution is actually at hand. To find it, just dig a little deeper in the W3C's publications. It's called Extensible Markup Language, or XML, and it could open the door to a flood of useful new tags.

SGML: The elder standard
XML is based on Standard Generalized Markup Language (SGML), the mother of all text markup languages, which was codified by the International Organization for Standardization (better known as ISO) more than a decade ago. HTML is an example of SGML in action - an SGML application created by Tim Berners-Lee for the first Web pages.

The example illustrates just how flexible SGML is. To create a new tag language, publishers simply create a document type definition (DTD) that defines the language and its tags. SGML-capable software knows how to read the DTD and applies the rules described to render the file.

From the Web's first days, SGML fans have longed for browsers that could read any SGML type, not just HTML. Unfortunately, SGML was just too hard to use and support, and it failed to win a following. Chastened but not defeated, the SGML partisans regrouped and have since streamlined the language and adapted it for use over networks. The result is XML.

Do-it-yourself markup language
When support for XML is in place, every publisher will theoretically be able to create tags by simply adding them to a document. You won't even need to create a DTD; style sheets or scripts can tell the browser how to treat each element.

The value of XML will be felt most keenly by industries such as banking or health care, which will be able to create tags and DTDs to structure and process the kind of specialized information that, at the current rate, would make it into the HTML spec sometime in the middle of the next millennium.

Designers of simpler publications can always just stick with HTML, but imagine being able to create a tagging system that describes your publication's structure and can then be used to build indexes that are really meaningful to your audience.

All this is a way off: The XML spec itself is still just a working draft at the W3C. But XML is already being built into the next browsers from Microsoft and Netscape, and by this time next year designers should be able to stop grousing about HTML's slow progress and see how it feels to create their own tags.

Darcy DiNucci (darcy@tothepoint.com) is co-author of "Elements of Web Design." She consults on electronic information design from her office in San Francisco.



Copyright © 1997 Ziff-Davis Inc. All rights reserved. Reproduction in whole or in part in any form or medium without express written permission of Ziff-Davis Inc. is prohibited. MacWEEK and the MacWEEK logo are trademarks of Ziff-Davis Inc.

Feedback Page