Information Today
Volume17, Number 3 • March 2000
World Wide Web Consortium Issues XHTML 1.0 as a Recommendation

The World Wide Web Consortium (W3C) has released the XHTML 1.0 specification as a W3C Recommendation. This new specification represents cross-industry and expert community agreement on the importance of XHTML 1.0 as a bridge to the Web of the future. A W3C Recommendation indicates that a specification is stable, contributes to Web interoperability, and has been reviewed by the W3C membership, who favor its adoption by the industry.

According to the announcement, HTML currently serves as the common language for millions of people publishing hypertext on the Web. While that is the case today, the future of the Web is written in W3C’s eXtensible Markup Language (XML). XML is bringing the Web forward as an environment that better meets the needs of all its participants, allowing content creators to make structured data that can be easily processed and transformed to meet the varied needs of users and their devices.

In designing XHTML 1.0, the W3C HTML Working Group faced a number of challenges, including one capable of making or breaking the Web: how to design the next-generation language for Web documents without making what’s already on the Web obsolete, and how to create a markup language that supports device independence. The answer was to take HTML 4.0 and rewrite it as an XML application; the first result is XHTML 1.0.

“XHTML 1.0 connects the present Web to the future Web,” said Tim Berners-Lee, W3C director. “It provides the bridge to page and site authors for entering the structured-data XML world, while still being able to maintain operability with user agents that support HTML 4.0.”

XHTML 1.0 allows authors to create Web documents that work with current HTML browsers and that may be processed by XML-enabled software as well. Authors writing XHTML 1.0 use the well-known elements of HTML 4.0 (to mark up paragraphs, links, tables, lists, etc.), but with XML syntax, which promotes markup conformance. The benefits of XML syntax include extensibility and modularity. With HTML, authors had a fixed set of elements to use, with no variation. With XHTML 1.0, authors can mix and match known HTML 4.0 elements with elements from other XML languages, including those developed by W3C for multimedia (Synchronized Multimedia Language—SMIL), mathematical expressions (MathML), two-dimensional vector graphics (Scalable Vector Graphics—SVG), and metadata (Resource Description Framework—RDF).

W3C provides instruction and tools for making the transition from HTML 4.0 to XHTML 1.0. The “HTML Compatibility Guidelines” section of the XHTML 1.0 Recommendation explains how to write XHTML 1.0 that will work with nearly all current HTML browsers. W3C offers validation services for both HTML and XHTML documents. W3C’s Open Source software “Tidy” helps Web authors convert ordinary HTML 4.0 into XHTML 1.0 and clean document markup at the same time.

In addition to its extensibility, moving from HTML to XML via XHTML 1.0 lays the foundation for making Web content available to millions more users. People browsing the Web with cell phones or other mobile devices want Web content tailored to their needs. People with disabilities need ways to transform content into accessible formats. XML documents can already be transformed using eXtensible Stylesheet Language Transformations (XSLT), and rendered using independent style sheets such as CSS (Cascading Style Sheets). XHTML 1.1, already under development, coupled with device-specific style sheets and Composite Capability/Preference Profiles (CC/PP)—a protocol that allows a user to describe both user preferences and device capabilities—will bring mobile and other devices to the Web as full participants.

The XHTML 1.0 Recommendation was written by members of the HTML Working Group, which includes key industry players such as Ask Jeeves, CNET, Gateway, GMD, Hewlett-Packard, HTML Writers Guild, IBM, JetForm, Microsoft, MITRE, Philips Electronics, Phone.com, Quark, Stack Overflow, Sun Microsystems, and WebTV Networks. To date, over 390 organizations are members of W3C.

Source: World Wide Web Consortium (Janet Daly, janet@w3c.org), 617/253-5884; http://www.w3c.org.


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