Recently, the W3C HTML Working Group published a new version of HTML5 Differences from HTML4 working draft. The latest version summarizes the differences between the W3C HTML5 and the W3C HTML 4 standards – a significant change from previous versions, which also covered the comparison between WHATWG HTML and W3C HTML 4.

HTML5 evangelist and former W3C team member, Klaus Birkenbihl, told InfoQ why WHATWG HTML has been ignored in this latest working draft.

There is a rather obvious reason for this. HTML5 will soon be an official stable W3C Recommendation (aka “W3C Standard”) and the “HTML5 Differences” working draft also shall become a standard one day. So moving targets like W3C's HTML5.1 drafts and WHATWG's “living standard” version of HTML had to be removed for stability.

Klaus added that a schism exists between the two standardization organizations.

WHATWG and W3C finally split in Jul 2012, when Ian Hickson stepped down as W3C HTML5 editor. Of course, the question is: is this relevant? And as often the answer is "it depends". In today's practice, a developer can work with either specification without experiencing any major problems. This is because browser vendors implement the specifications with different speeds and different priorities. So differences and restrictions listed e.g. on caniuse.com (a site that keeps track of HTML5 and CSS3 features in different browser versions) might be much more important for developers than the few existing differences in the specifications. From a developer’s point of view, the schism between W3C and WHATWG is not really threatening as long as major browser vendors work together in both groups in their well-understood own interests and not to split the Web.

Worry about the relationship of the “standardizing couple” is a long-lasting concern, though both W3C and WHATWG have been trying to minimize the divergence. Most recently, Jeff Jaffe, CEO of W3C, posted on the official blog of W3C, discussing which is better: W3C’s consensus process or WHATWG’s informed editor process. He first summarized OpenStand’s five fundamental principles of standards development (due process, broad consensus, transparency, balance and openness) and explained why the W3C’s consensus process is important for the entire ecosystem and for developing standards as critical and pervasive as web standards. But he also admitted that both the W3C’s and the WHATWG’s processes have their own pros and cons, and W3C “have much to learn from other processes such as 'decisions by informed editors'", to gain speed and agility in response to the industry needs. He mentioned “some of the key recent process innovations that W3C has taken to get the best of both worlds”, including community groups, process revision, modularity, improving W3C’s plans for spec iteration and errata management.