"This specification defines the 5th major revision of the core language of the World Wide Web, HTML. In this version, new features are introduced to help Web application authors, new elements are introduced based on research into prevailing authoring practices, and special attention has been given to defining clear conformance criteria for user agents in an effort to improve interoperability."HTML 5 appears to be a philosophical split from XHTML 2. Whereas XHTML 2 is for representing documents on screens and print, HTML 5 seems to be for interactive computer interfaces. For example:
"XHTML2 [XHTML2] defines a new HTML vocabulary with better features for hyperlinks, multimedia content, annotating document edits, rich metadata, declarative interactive forms, and describing the semantics of human literary works such as poems and scientific papers.Much of the philosophy of HTML 5 seems to be embedded in the Apple iPhone. But that device can use ordinary old HTML web pages with CSS to adapt web pages for iPhones and other smartphones.
However, it lacks elements to express the semantics of many of the non-document types of content often seen on the Web. For instance, forum sites, auction sites, search engines, online shops, and the like, do not fit the document metaphor well, and are not covered by XHTML2. "
Also the tone of the document, especially the editor's comments, seem to be much more confrontational, than XHTML's academic style. The HTML 5 editors are essentially saying that they are going to produce a usable standard and so everyone either needs to get on board or get out of their way. An example is:
"Implementors should be aware that this specification is not stable. Implementors who are not taking part in the discussions are likely to find the specification changing out from under them in incompatible ways. Vendors interested in implementing this specification before it eventually reaches the Candidate Recommendation stage should join the aforementioned mailing lists and take part in the discussions."Much of what the authors are saying makes sense, but the way they are saying it is likely to not go down well in consensus based forums.