The WHATWG was formed in response to the slow development of
World Wide Web Consortium (W3C)
Web standards and W3C's decision to abandon HTML in favor of
XML-based technologies. The WHATWG mailing list was announced on 4 June 2004, two days after the initiatives of a joint Opera–Mozilla position paper had been voted down by the W3C members at the W3C Workshop on Web Applications and Compound Documents. On 10 April 2007, the Mozilla Foundation, Apple, and Opera Software proposed that the new HTML working group of the W3C adopt the WHATWG's
HTML5 as the starting point of its work and name its future deliverable as "HTML5" (though the WHATWG specification was later renamed
HTML Living Standard). On 9 May 2007, the new HTML working group of the W3C resolved to do that. An
Internet Explorer platform architect from
Microsoft was invited but did not join, citing the lack of a patent policy to ensure all specifications can be implemented on a
royalty-free basis. Since then, the W3C and the WHATWG had been developing HTML independently, at times causing specifications to diverge. In 2017, the WHATWG established an
intellectual property rights agreement that includes a patent policy. This spurred a renewed attempt to allow the W3C and the WHATWG to work together on specifications. In 2019, the W3C and WHATWG agreed to a
memorandum of understanding where development of HTML and DOM specifications would be done principally in the WHATWG. In one case, editor
Ian Hickson proposed replacing the tag with a more generic tag, but the community disagreed and the change was reverted. along with variant abbreviations including
WHAT Working Group,
WHAT Task Force and
WHATTF. After some time using both the and
domain names,
Transition of HTML Publication to WHATWG On 28 May 2019, the W3C announced that WHATWG would be the sole publisher of the HTML and DOM standards. The W3C and WHATWG had been publishing competing standards since 2012. While the W3C standard was identical to the WHATWG in 2007 the standards have since progressively diverged due to different design decisions. The WHATWG "Living Standard" had been the de facto web standard for some time. ==Specifications==