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W3C Gives Thumbs-Up to DOM Level 2

The World Wide Web Consortium (W3C) Monday laid down the law on Application Programming Interfaces (API) for manipulating documents and data through programming languages.

Okay, it wasn't quite the law. The W3C -- an international industry group made up of 470 organizations and run jointly by the MIT Laboratory for Computer Science in the U.S., The National Institute for Research in Computer Science and Control in France, and Keio University in Japan -- only recommended that Web developers adopt the Document Object Model (DOM) Level 2 specification. But that recommendation has some heft -- industry big boys like Macromedia, IBM, Microsoft, Netscape, Oracle, Sun Microsystems, SoftQuad Software and Nexgenix have thrown their weight behind the W3C's recommendation.

The W3C's DOM is a standard internal representation of document structure and aims to make it easy for programmers to access components and delete, add or edit their content, attributes or style. Basically, the DOM makes it possible to write applications which work properly on all browsers and servers and on all platforms. DOM Level 2 creates a common paradigm for representing Extensible Markup Language (XML) documents and data, including namespace support, a style sheet platform which adds support for Cascading Style Sheets (CSS) 1 and CSS 2, a standard model of how these objects may be combined, and a standard interface for accessing and manipulating them.

"The DOM Level 2 Recommendation builds on the solid work done in DOM Level 1, and gives Web authors the power to move to XML for dynamic content," said Lauren Wood of SoftQuad Software, chairman of the W3C DOM Working Group. "The DOM also provides developers with the interoperability and integration ability they need. There are now several implementations of the DOM, in different programming languages, which provide the basis of powerful systems meeting the business needs of several large organizations."

The first DOM specification, DOM Level 1, was recommended by the group in 1998. It was designed for HTML 4.0 and XML 1.0. The new specification takes further advantage of XML's extensibility.

"Simply put, anywhere you use XML, you can now use the DOM to manipulate it," the W3C said.

DOM Level 2's standard interface makes it possible to write language- and platform-independent tag-sets, while the standard API enables authors to write programs that work without changes across tools and browsers from different vendors. It also provides a uniform way to produce programs that work across a variety of devices. An Events API is also included to provide interactivity anywhere XML is used, whether in documents, data or B2B applications.

"As the Web continues to evolve, the value of a core set of DOM features grows ever more important," said David Turner, product manager and technical evangelist, XML Technologies, Microsoft Corp. "Those core features provide content and application developers alike with a common programming model across a variety of languages and applications, which has been a direct contributor to the success of XML."

With DOM Level 2 reviewed and recommended, the W3C DOM Working Group is now developing DOM Level 3, which will address document loading and saving, as well as content models (such as DTDs and schemas) with document validation support. It will also address documents views and formatting, key events and event groups.. Other W3C Working Groups are also working to extend the DOM Level 2 platform for Scalable Vector Graphics (SVG) and Mathematical Markup Language (MathML).