Mozilla, Opera, and Apple have advised the W3C to adopt the HTML 5 work from WHATWG.
HTML 5 specifies existing HTML4 markup and APIs with much clearer conformance criteria for both implementations and documents. It specifies many useful additions, in many cases drawing on features that have existed in browser-based implementations for a long time. And it actively draws on feedback from implementers and content authors.
HTML5, comprising the Web Apps 1.0 and Web Forms 2.0 specifications, is the product of many years of collaborative effort.
Apple, Mozilla and Opera will agree to arrange a non-exclusive copyright assignment to
the W3 Consortium for HTML5 specifications.