W3C Readies XHTML For Approval.
At the end of August, the World Wide Web Consortium (W3C (World Wide Web Consortium, www.w3.org) An international industry consortium founded in 1994 by Tim Berners-Lee to develop standards for the Web. It is hosted in the U.S. by the Computer Science and Artificial Intelligence Laboratory (CSAIL) at MIT (www.csail.mit.edu/index.php). ) moved the newest incarnation of HTML HTML
in full HyperText Markup Language
Markup language derived from SGML that is used to prepare hypertext documents. Relatively easy for nonprogrammers to master, HTML is the language used for documents on the World Wide Web. , called XHTML (EXtensible HTML) A markup language for Web pages from the W3C. XHTML combines HTML and XML into a single format (HTML 4.0 and XML 1.0). Like XML, XHTML can be extended with proprietary tags. Also like XML, XHTML must be coded more rigorously than HTML. , into its Proposed Recommendation review phase, the next-to-last step before XHTML becomes an official Recommendation. The next-generation Web standard--for all purposes a merger of HTML and XML--should be approved by the time you read this.
XHTML is the most significant change to the language of the Web since HTML 4.0 was approved in 1997. XHTML is a family of document types and modules that extend the functionality of HTML 4.0 and has its roots in XML XML
in full Extensible Markup Language.
Markup language developed to be a simplified and more structural version of SGML. It incorporates features of HTML (e.g., hypertext linking), but is designed to overcome some of HTML's limitations. . Documents based on XHTML are designed to work with the new wave of Web-enabled devices, including cell phones and PDAs.
In brief, XHTML documents conform to Verb 1. conform to - satisfy a condition or restriction; "Does this paper meet the requirements for the degree?"
coordinate - be co-ordinated; "These activities coordinate well" XML and can be viewed, edited, and validated with standard XML tools. However, XHTML documents can also be viewed by existing HTML 4.0-compliant browsers and other user agents. XHTML documents can also run processes (scripts and applets) that are based on the HTML Document Object Model (DOM) or the XML DOM.
XHTML contains several important syntax changes from HTML. Since XML is case-sensitive, XHTML documents must use lower case for all HTML element and attribute names. Also, XHTML is strict in its interpretation of tags; this means that all elements must either have closing tags or be written in a special form, and that all the elements must nest. For example, the widely used new paragraph [less than]p[greater than] tag, which creates a paragraph break, is often used without its closing partner [less than]/p[greater than]. This is unacceptable in XHTML. Other changes include the need for quotes in attribute values. For example, the attribute tag [less than]table rows="3"[greater than] is correct; [less than]table rows=3[greater than] is incorrect.
In creating XHTML documents, authors should note that pages can be labeled as text/html, text/xml, or application/xml. When labeled as text/html, however, documents that don't follow standard HTML Compatibility Guidelines will almost certainly fail to be processed, according to XHTML documentation.
The need for a new Web language has become increasingly obvious. According to the W3C, some estimates indicate that by 2002, fully 75 percent of Internet document viewing will be carried out on alternate platforms--that is, non PC-based applications. New protocols like WAP (1) (Wireless Access Point) See access point.
(2) (Wireless Application Protocol) A standard for providing cellular phones, pagers and other handheld devices with secure access to e-mail and text-based Web pages. , which target small-footprint microbrowsers, are already implementing XML. However, Web content must be written specifically in WML (Wireless Markup Language) A tag-based language used in the Wireless Application Protocol (WAP). WML is an XML document type allowing standard XML and HTML tools to be used to develop WML applications. It evolved from Openwave's HDML, but WML is not a superset of HDML. , WAP's markup language, in order to be processed quickly and efficiently. XHTML will give page designers more leeway in their coding of content, allowing devices on multiple platforms to access the same data. (See the September issue of CTR See click-through rate. for a complete discussion of WAP.)
More XHTML information, including the complete specification, is available at www.w3.org/MarkUp/#news.