"This is the first time we've been able to answer people's questions of when it will be done," said Ian Jacobs, head of W3C marketing and communications. "More and more people from more and more industries are asking when it will be done. They require stability in the standard and very high levels of interoperability."
HTML5 is the next version of the HyperText Markup Language, a platform-neutral standard used worldwide for rendering Web pages. Concerns over when the standard would be finalized have escalated in recent years, as Apple, Google and Microsoft touted the still-unfinished standard as the basis for building Web applications.
Despite the enthusiasm of those companies and others, many have cautioned against using the standard before it is finalized. Because of its complexity, estimates as to when HTML5 would be finished have varied wildly, from a year or two to not until 2022.
The last call for feedback has already been announced, for May 22 this year.
From then until 2014, the HTML Working Group will have several tasks to complete before the standard is finalized, Jacobs said. The group has to review and address the comments submitted up to the May deadline. The feedback from this "Last Call" is expected to be quite considerable and could result in another revision of the document.
The group also has to design a test suite, one that can encompass the wide range of different browsers and platforms that will render pages and Web applications written in HTML5.
Such interoperability is crucial, given the expanding range of devices accessing the Web, including televisions, tablets and phones. "The target is broad interoperability," Jacobs said.
The W3C expects no new features to be added after the Last Call. From that point on the group will take feedback only from implementers and through trials of the test suite, said Philippe Le Hégaret, lead for the W3C Interaction Domain, which oversees the development of HTML, CSS (Cascading Style Sheets), SVG (Scalable Vector Graphics) and other Web standards.
As the working group finalizes HTML5 it will start considering new features and improvements for subsequent versions. While members of the working group have decreed they will do away with version numbering of the standard, neither Jacobs nor Le Hégaret would definitively state that there won't be future numbered versions, such as an HTML6 or HTML5.1.
For now, the organization will classify the work being done under the working title of "HTML.next," Jacobs said.
The W3C also announced on Monday that it has extended the charter of the HTML Working Group to 2014. The HTML Working Group is comprised of more than 400 members from browser vendors, software developers and other organizations reliant on the Web standard.
