HTML and CSS Reference
In-Depth Information
HTML5 Overview
HTML5 offers new features (elements, attributes, event handlers, and APIs) for easier web
application development and more sophisticated form handling.
The HTML5 specification is based on HTML 4.01 Strict, but unlike previous HTML Recom-
mendations, HTML5 does not use a Document Type Definition (DTD). Instead, it uses the
Document Object Model (DOM, the “tree” formed by a document's structure) as its basis
rather than a particular set of syntax rules. It also differs from previous recommendations in
that it includes detailed instructions for how browsers should handle malformed and legacy
markup.
W3C and WHATWG
There are two organizations maintaining slightly different HTML specifications as of this
writing.
HTML5wasoriginallywrittenbytheWebHypertextApplicationTechnologyWorkingGroup
(WHATWG). In 2003, members of Apple, Mozilla, and Opera formed the WHATWG to fur-
ther the development of HTML in a way that was consistent with real-world authoring prac-
tices and browser behavior. Their initial documents, Web Applications 1.0 and Web Forms
1.0, were rolled together into HTML5, which is still in development under the guidance of
WHATWG editor, Ian Hickson. They eventually dropped the version number and now main-
tain “living” (unnumbered) HTML specification at
whatwg.org
.
In 2006, the World Wide Web Consortium (W3C) formed its own HTML5 Working Group
based on the work by the WHATWG. In 2009, it discontinued its work on XHTML 2.0 in
order to focus on the development of HTML5. The W3C maintains a “snapshot” (numbered)
version of HTML5 (
www.w3.org/TR/html5/
)
, which is expected to reach Recommendation
status in 2014. HTML5.1 is also in development and is scheduled to become a Recommenda-
tion in 2016. Nightly builds of the HTML5.1 Editor's Draft are available at
www.w3.org/html/
The differences between the W3C and HTML5 Candidate Recommendation and the
WHATWG versions are fairly minor. The WHATWG and HTML5.1 spec change frequently,
but the differences as of this writing include:
