The World Wide Web Consortium (W3C) last Wednesday recommended use of XHTML (Extensible HTML) 1.0 specification to expand the use of XML (Extensible Markup Language) without making existing HTML elements obsolete.
XHTML 1.0 was created by rewriting HTML 4 as an XML application, creating a specification that will work with HTML browsers and take advantage of XML's device-independent capabilities. According to Janet Daly, a spokesperson for the W3C, XHTML 1.0 will act as a `bridge' to connect the mostly-HTML-based Web with the benefits of XML.
`The world of the Web today, as we know it, is an HTML world,' said Daly. `HTML handles display adequately but really doesn't allow for data manipulation. You can use style sheets in conjunction with HTML, but it doesn't change the structure of the document; it only changes the presentation aspect. As the Web is moving toward XML, it has become apparent that even Web users and authors of today using HTML want to be able to do more; they want to reach more of the new users that are now demanding Web access.'
As a W3C recommendation, the XHTML 1.0 specification `is stable, contributes to Web interoperability, and has been reviewed by the W3C membership, who favour its adoption'.
Developers already writing HTML 4 documents should have a smooth transition into XHMTL 1.0, Daly said, noting that the W3C provides tools to convert HTML 4 documents into XHTML, and that `the tag set, the elements, and attributes [for XHTML] are all HTML 4, so there's no learning curve there.' With the new specification, content developers will also be able to sidestep the problem of rewriting documents for several different device types.
`[Rewriting those documents] is a lot of work, and it also can sometimes lead to having a Web for one kind of device and a Web for another,' Daly said. `The W3C aims to ensure universality for the Web so that it's one universal information space in which all devices can be equal participants.'
The growing number of wireless and mobile devices, such as Internet-enabled cell phones and Palm-type handhelds, was a major part of the impetus behind the W3C's recommendation.
`XHTML 1.0 lays the groundwork for modularity, the ability to do structured transformations of documents,' Daly explained. `XHTML 1.1 work, now in development, is focused on the modularisation of XHTML. The W3C Mobile Access Activity is also developing a technology that allows for device profiling, called CC/PP. Together, these technologies may make it possible, in a uniform way, for your cell phone to explore the Web by identifying itself to a server. Then, the requested XHTML module would be delivered to the user in a way that suits the device and user.'