HTML is currently defined in multiple documents, each purporting to be THE definition of HTML/HTML5. The documents are developed, published and maintained by 2 separate organisations. The 2 organisations have differing development models, one (W3C) employs a consensus process for resolving conflicts about the normative and informative content of the HTML specification, in the other (WHATWG) all decisions about what is in the specification are made by one person (the editor, Ian Hickson).
The W3C process has over time resulted in consensus based decision’s that Ian Hickson has not agreed with, the end result being that normative and informative content changes have been made to the W3C HTML5 specification that have not been made to the WHATWG HTML living standard and vice versa. It is interesting to note that the majority of these differences relate to accessibility. Below are the intentional accessibility related differences introduced by Ian Hickson, so far:
Working Group Decision on ISSUE-131 caret-location-api
The WHATWG living standard omits a whole section of implementation requirements for making canvas content more accessible to people with disabilities.
Working Group Decision on ISSUE-66 – Image Analysis Heuristics
The WHATWG Living standard includes a paragraph of implementation advice in regards to image analysis heuristics that is considered not helpful to anyone.
Working Group Decision on ISSUE-109 aria-section-title
The WHATWG living standard omits a paragraph encouraging implementers to make WAI-ARIA features useful to a wider range of people with disabilities and anybody else who they may be useful to.
Working Group Decision on ISSUE-122 shalott-example
The WHATWG living standard defines normative requirements that forbid authors from providing text alternatives for emotionally rich images.
The WHATWG Living standard omits a link to HTML to Platform Accessibility APIs Implementation Guide, a work in progress designed to provide the significant amount of accessibility implementation advice not provided in HTML.
Working Group Decision on ISSUE-130: table-layout
The WHATWG living standard omits advice on how authors can mitigate the negative accessibility effects of layout tables.
Working Group Decision on ISSUE-31 / ISSUE-80 validation survey
The WHATWG living standard allows authors of HTML emails to omit text alternatives for images.
The WHATWG living standard includes a clause that requires conformance checkers to emit errors for use of ARIA roles in cases where their use improves the accessibility of the content.
WHATWG living standard includes a clause that requires conformance checkers to emit errors for use of ARIA roles in cases where their use improves the accessibility of canvas content.
Who exactly benefits from the divergence of normative requirements and advice across documents claiming to authoritatively define HTML? If forking is bad for HTML what are the parties involved doing to to remedy it? I have asked people involved, but as yet no answers have been forthcoming.