News: New XHTML carries a language barrier
As the Web marches into the future, some developers say they're concerned about what will become of its past.

At stake are new specifications approved by the Web's leading standards body that would complete the transition from HTML to XML as the fundamental language used to build Web pages.

Of primary concern to some Web developers is the W3C's warning that XHTML 2.0 will not be "backward compatible" with HTML 4.0 and XHTML 1.0. That alert has raised concern that billions of existing Web pages risk obsolescence unless they are translated to the new Web language.

Most developers see any significant clash between the old and new languages as a long way off. But some say the lack of compatibility will immediately hold them back from switching to XHTML 2.0, a reluctance that could complicate what many see as a necessary evolution for the Web.

"I'm really hesitant over the line in the new spec (v2) that reads, 'While the ancestry of XHTML 2 comes from HTML 4, XHTML 1.0, and XHTML 1.1, it is not intended to be backward compatible with its earlier versions,'" Frances Currit-Dhaseleer, a technical trainer and Webmaster in Colorado Springs, Colo., wrote in an e-mail interview. "What exactly does this mean? Does this mean that everything else is obsolete? If that's the case, it'll be a long time before I move over to XHTML."

XHTML, first recommended by the W3C in January 2000, attempted to redesign the Web's standard markup language from HTML, which was increasingly considered a jerry-built, relatively unstructured improvisation on the earlier Standard Generalized Markup Language (SGML).

The HTML-XML hybrid
At a W3C meeting four years ago, the consortium's members decided on a gradual shift away from HTML. XHTML 1.0 was created as a hybrid to start weaning the Web's developers and authoring tool makers away from the legacy markup language and over to a new XML-based future.

"XHTML 1.0 was designed as a bridge between HTML and XML," said Ann Navarro, president and founder of WebGeek, a consulting firm in Port Charlotte, Fla., and an editor of the XHTML 2.0 working draft. "XHTML 2.0 is 'the other side' of that bridge, dropping much of the deprecated content and moving forward into new, more 'XML' methods of accomplishing tasks."

It may be a while before Web authors and surfers begin to encounter evidence of XHTML 2.0 incompatibility with legacy HTML and XHTML 1.0 code.

That will occur only when browsers start supporting XHTML 2.0 and stop supporting its predecessors, a process that will likely take years after the W3C finally issues the new specification as a recommendation.

But Navarro warned that it was only a matter of time before that transformation occurred.

"There's going to be a cut-off point," Navarro said. "I don't know when it's going to be, in the next version of the browsers or at some other time, but there will be a cut-off point. If we're going to move the Web to XML, we've got to move it."
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