The HTML5 draft reflects an effort, started in 2004, to study contemporary HTML implementations and deployed content . The draft: Defines a single language called HTML 5 which can be written in HTML (HTML5) and XML (XHTML5). Defines detailed processing models to foster interoperable implementations. Improves markup for documents. Introduces markup and APIs for emerging idioms, such as web applications. Not sure what happened to XHTML drafts, maybe they have to keep it HTML until browsers fully support XHTML, anyway HTML 5 has many new tags that would fill many of HTML4 gaps [tags] markup tags, apis, implementations, web applications, gaps, idioms, xml, models [/tags]