A Quite Biased History of HTML5
1. “content type” or “MIME type” in response header is the only thing that determines what a particular resource truly is, and therefore how it should be rendered. Images, JavaScript files and CSS stylesheets all have their own MIME types. Everything has its own MIME type. The web runs on MIME types.
2. HTML has always been a conversation between browser makers, authors, standards wonks, and other people who just showed up and liked to talk about angle brackets. Most of the successful versions of HTML have been “retro-specs,” catching up to the world while simultaneously trying to nudge it in the right direction. Anyone who tells you that HTML should be kept “pure” (presumably by ignoring browser makers, or ignoring authors, or both) is simply misinformed. HTML has never been pure, and all attempts to purify it have been spectacular failures, matched only by the attempts to replace it.
3. XHTML 1.0 defined a new MIME type for XHTML documents, application/xhtml+xml . However, to ease the migration of existing HTML 4 pages, it also included Appendix C , that “summarizes design guidelines for authors who wish their XHTML documents to render on existing HTML user agents.” Appendix C said you were allowed to author so-called “XHTML ” pages but still serve them with the text/html MIME type. XHTML 1.1 added only a few minor features on top of XHTML 1.0, but also eliminated the “Appendix C” loophole. With an estimated error rate of 99% on existing pages, the ever-present possibility of displaying errors to the end user, and the dearth of new features in XHTML 1.0 and 1.1 to justify the cost, web authors basically ignored application/xhtml+xml . they “upgraded” to XHTML syntax but kept serving it with a text/html MIME type.
4. WHAT Working Group(Web Hypertext Applications Technology Working Group) took a different approach: documenting the “forgiving” error-handling algorithms that browsers actually used. They spent five years successfully documenting how to parse HTML in a way that is compatible with existing web content. WHAT working group was on a specification, initially dubbed Web Forms 2.0 , that added new types of controls to HTML forms. Another was a draft specification called “Web Applications 1.0,” that included major new features like a direct-mode drawing canvas and native support for audio and video without plugins .
5. In October 2006, W3C chartered a completely new HTML group with WHAT working group. One of the first things the newly re-chartered W3C HTML Working Group decided was to rename “Web Applications 1.0” to “HTML5.”