HTML, an initialism of HyperText Markup Language, is the
predominant markup language for Web pages. It provides a
means to describe the structure of text-based information
in a document — by denoting certain text as links, headings,
paragraphs, lists, and so on — and to supplement that text
with interactive forms, embedded images, and other objects.
HTML is written in the form of tags, surrounded by angle
brackets. HTML can also describe, to some degree, the appearance
and semantics of a document, and can include embedded scripting
language code (such as JavaScript) which can affect the
behavior of Web browsers and other HTML processors.
In 1980, physicist Tim Berners-Lee, who was an independent
contractor at CERN, proposed and prototyped ENQUIRE, a system
for CERN researchers to use and share documents. In 1989,
Berners-Lee and CERN data systems engineer Robert Cailliau
each submitted separate proposals for an Internet-based
hypertext system providing similar functionality. The following
year, they collaborated on a joint proposal, the WorldWideWeb
(W3) project,[1] which was accepted by CERN.
[edit] First specifications
The first publicly available description of HTML was a document
called HTML Tags, first mentioned on the Internet by Berners-Lee
in late 1991.[2][3] It describes 22 elements comprising
the initial, relatively simple design of HTML. Thirteen
of these elements still exist in HTML 4.[4]
Berners-Lee considered HTML to be, at the time, an application
of SGML, but it was not formally defined as such until the
mid-1993 publication, by the IETF, of the first proposal
for an HTML specification: Berners-Lee and Dan Connolly's
"Hypertext Markup Language (HTML)" Internet-Draft,
which included an SGML Document Type Definition to define
the grammar.[5] The draft expired after six months, but
was notable for its acknowledgment of the NCSA Mosaic browser's
custom tag for embedding in-line images, reflecting the
IETF's philosophy of basing standards on successful prototypes.[6]
Similarly, Dave Raggett's competing Internet-Draft, "HTML+
(Hypertext Markup Format)", from late 1993, suggested
standardizing already-implemented features like tables and
fill-out forms.[7]
After the HTML and HTML+ drafts expired in early 1994,
the IETF created an HTML Working Group, which in 1995 completed
"HTML 2.0", the first HTML specification intended
to be treated as a standard against which future implementations
should be based.[6] Published as Request for Comments 1866,
HTML 2.0 included ideas from the HTML and HTML+ drafts.[8]
There was no "HTML 1.0"; the 2.0 designation was
intended to distinguish the new edition from previous drafts.[9]
Further development under the auspices of the IETF was
stalled by competing interests. Since 1996, the HTML specifications
have been maintained, with input from commercial software
vendors, by the World Wide Web Consortium (W3C).[10] However,
in 2000, HTML also became an international standard (ISO/IEC
15445:2000). The last HTML specification published by the
W3C is the HTML 4.01 Recommendation, published in late 1999.
Its issues and errors were last acknowledged by errata published
in 2001.
HyperText
Markup Language (HTML)