UPDATED Two of Microsoft's rivals in the browser space have joined forces on a standards proposal slated to be presented to a W3C workshop.

The Mozilla Foundation and Opera Software collaborated on the document, which represents their "consensus" opinion in the context of standards for Web Applications, and Compound Documents.

The working document of the draft specification is titled Web Forms 2.0 which is in its essence an extension of the way forms are defined in the existing HTML 4.01 forms chapter, though it will apply equally to XHTML (define) user agents as well. The proposed specifications include new attributes, DOM (define) interfaces and events for validation and dependency tracking as well as XML form submission and initialization. The specification also aims to document existing practices in the forms area that have not yet been officially standardized.

"We consider Web Applications to be an important area that has not been adequately served by existing technologies," the paper stated in its opening paragraph. "There is a rising threat of single-vendor solutions addressing this problem before jointly developed specifications. To compete with other players in this field, user agents with initial implementations of jointly-developed specifications should ideally be shipping before the end of the year 2004."

Ian Hickson of Opera Software, one of the authors, said he believes it is important that both Mozilla and Opera support the specification for a number of reasons, including interoperability.

"The whole point of standards is that they be supported by all the vendors. If there is only one vendor that supports a standard, it might as well be a proprietary standard," Hickson told internetnews.com. "Proprietary technologies are not good for authors and users, since they lock you in to one vendor."

Hickson predicts that if a backwards-compatible open-standards alternative isn't created first, then 10 years from now the de facto Web application standard will be Microsoft's Avalon and the .NET framework. Microsoft will also be presenting an overview of the Longhorn "Avalon" technology XAML (define) at the W3C workshop as well.

"If the W3C (or another group) develop an open standard that is backwards compatible with HTML and DOM and can be implemented in Windows IE6 without binary plug-ins, and this technology gets implemented by the vendors like Opera and Mozilla, then I hope authors will want to use that solution instead of Avalon and .NET," Hickson said.

According to Hickson, getting buy-in from both Mozilla and Opera was a non-issue. "This is what everyone here has been saying for a long time," he said.

In terms of community responses so far to the paper and the spec, in advance of the W3C workshop, however, Hickson admits that the feedback is less than he was expecting.

"It's rather amusing in that I got more feedback when I wrote a Web log posting about how to embed Flash into HTML using only 'object' elements than I did when I mentioned what Opera and Mozilla thought of the future of the Web," Hickson mused. "I think that rather demonstrates our point, though, that being compatible with Windows IE6 is what matters to authors today."

Updates prior version to correct Hickson's first name