History of HTML

Tim Berners-Lee created the original HTML (and many of the associated protocols such as HTTP) on a NeXTcube workstation using the NeXTSTEP development environment. At the time, HTML was not a specification, but a collection of tools to solve an immediate problem: the communication and dissemination of ongoing research among Berners-Lee and a group of his colleagues. His solution later combined with the emerging international and public internet to garner worldwide attention.Early versions of HTML were defined with loose syntactic rules, which helped its adoption by those unfamiliar with web publishing. Web browsers commonly made assumptions about intent and proceeded with rendering of the page. Over time, the trend in the official standards has been to create an increasingly strict language syntax; however, browsers still continue to render pages that are far from valid HTML.HTML is defined in formal specifications that were developed and published throughout the 1990s, inspired by Tim Berners-Lee's prior proposals to graft hypertext capability onto a homegrown SGML-like markup language for the Internet. The first published specification for a language called HTML was drafted by Berners-Lee with Dan Connolly, and was published in 1993 by the IETF as a formal "application" of SGML (with an SGML Document Type Definition defining the grammar). The IETF created an HTML Working Group in 1994 and published HTML 2.0 in 1995, but 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).[1] 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 and its issues and errors were last acknowledged by errata published in 2001.Since the publication of HTML 4.0 in late 1997, the W3C's HTML Working Group has increasingly — and since 2002, exclusively — focused on the development of XHTML, an XML-based counterpart to HTML that is described on one W3C web page as HTML's "successor".[2][3][4] XHTML applies the more rigorous, less ambiguous syntax requirements of XML to HTML to make it easier to process and extend, and as support for XHTML has increased in browsers and tools, it has been embraced by many web standards advocates in preference to HTML. XHTML is routinely characterized by mass-media publications for both general and technical audiences as the newest "version" of HTML, but W3C publications, as of 2006, do not make such a claim; neither HTML 3.2 nor HTML 4.01 have been explicitly rescinded, deprecated, or superseded by any W3C publications, and, as of 2006, they continue to be listed alongside XHTML as current Recommendations in the W3C's primary publication indices.[5][6][7]Version history of the standardHypertext Markup Language (First Version), published June 1993 as an Internet Engineering Task Force (IETF) working draft (not standard).HTML 2.0, published November 1995 as IETF RFC 1866, supplemented by RFC 1867 (form-based file upload) that same month, RFC 1942 (tables) in May 1996, RFC 1980 (client-side image maps) in August 1996, and RFC 2070 (internationalization) in January 1997; ultimately all were declared obsolete/historic by RFC 2854 in June 2000.HTML 3.2, published January 14, 1997 as a W3C Recommendation.HTML 4.0, published December 18, 1997 as a W3C Recommendation. It offers three "flavors":Strict, in which deprecated elements are forbiddenTransitional, in which deprecated elements are allowedFrameset, in which mostly only frame related elements are allowed.HTML 4.01, published December 24, 1999 as a W3C Recommendation. It offers the same three flavors as HTML 4.0, and its last errata was published May 12, 2001.ISO/IEC 15445:2000 ("ISO HTML", based on HTML 4.01 Strict), published May 15, 2000 as an ISO/IEC international standard.HTML 4.01 and ISO/IEC 15445:2000 are the most recent and final versions of HTML. HTML's successor, XHTML, is a separate language that began as a reformulation of HTML 4.01 using XML 1.0. It continues to be developed:XHTML 1.0, published January 26, 2000 as a W3C Recommendation, later revised and republished August 1, 2002. It offers the same three flavors as HTML 4.0 and 4.01, reformulated in XML, with minor restrictions.XHTML 1.1, published May 31, 2001 as a W3C Recommendation. It is based on XHTML 1.0 Strict, but includes minor changes and is reformulated using modules from Modularization of XHTML, which was published April 10, 2001 as a W3C Recommendation.XHTML 2.0 is still a W3C Working Draft.There is no official standard HTML 1.0 specification because there were multiple informal HTML standards at the time. However, some people consider the initial edition provided by Tim Berners-Lee to be the definitive HTML 1.0. That version did not include an IMG element type. Work on a successor for HTML, then called "HTML+", began in late 1993, designed originally to be "A superset of HTML…which will allow a gradual rollover from the previous format of HTML". The first formal specification was therefore given the version number 2.0 in order to distinguish it from these unofficial "standards".Work on HTML+ continued, but it never became a standard.The HTML 3.0 standard was proposed by the newly formed W3C in March 1995, and provided many new capabilities such as support for tables, text flow around figures, and the display of complex math elements. Even though it was designed to be compatible with HTML 2.0, it was too complex at the time to be implemented, and when the draft expired in September 1995, work in this direction was discontinued due to lack of browser support. HTML 3.1 was never officially proposed, and the next standard proposal was HTML 3.2 (code-named "Wilbur"), which dropped the majority of the new features in HTML 3.0 and instead adopted many browser-specific element types and attributes which had been created for the Netscape and Mosaic web browsers. Math support as proposed by HTML 3.0 finally came about years later with a different standard, MathML.HTML 4.0 likewise adopted many browser-specific element types and attributes, but at the same time began to try to "clean up" the standard by marking some of them as deprecated, and suggesting they not be used.Minor editorial revisions to the HTML 4.0 specification were published as HTML 4.01.The most common filename extension for files containing HTML is .html. However, older operating systems and filesystems, such as the DOS versions from the 80's and early 90's and FAT, limit file extensions to three letters, so a .htm extension is also used. Although perhaps less common now, the shorter form is still widely supported by current software.HTML as a hypertext formatHTML is the basis of a comparatively weak hypertext implementation. Earlier hypertext systems had features such as typed links, transclusion and source tracking. Another feature lacking today is fat links.[8]Even some hypertext features that were in early versions of HTML have been ignored by most popular web browsers until now, such as the link element and editable web pages.Sometimes web services or browser manufacturers remedy these shortcomings. For instance, members of the modern social software landscape such as wikis and content management systems allow surfers to edit the web pages they visit