HTML was originally developed by Tim Berners-Lee while at CERN, and popularized by the Mosaic browser developed at NCSA. During the course of the 1990s it has blossomed with the explosive growth of the Web. During this time, HTML has been extended in a number of ways. The Web depends on Web page authors and vendors sharing the same conventions for HTML. This has motivated joint work on specifications for HTML. Most people agree that HTML documents should work well across different browsers and platforms. Achieving interoperability lowers costs to content providers since they must develop only one version of a document. If the effort is not made, there is much greater risk that the Web will devolve into a proprietary world of incompatible formats, ultimately reducing the Web's commercial potential for all participants. Each version of HTML has attempted to reflect greater consensus among industry players so that the investment made by content providers will not be wasted and that their documents will not become unreadable in a short period of time. HTML has been developed with the vision that all manner of devices should be able to use information on the Web: PCs with graphics displays of varying resolution and color depths, cellular telephones, hand held devices, devices for speech for output and input, computers with high or low bandwidth, and so on.The Hypertext Markup Language (HTML) is a simple markup language used to create hypertext documents that are platform independent. HTML documents are SGML documents with generic semantics that are appropriate for representing information from a wide range of domains. HTML markup can represent hypertext news, mail, documentation, and hypermedia; menus of options; database query results; simple structured documents with in-lined graphics; and hypertext views of existing bodies of information.
HTML2.0
HTML 2.0 (November 1995, was developed under the aegis of the Internet Engineering Task Force (IETF) to codify common practice in late 1994. HTML+ (1993) and HTML 3.0 (1995, it proposed much richer versions of HTML. Despite never receiving consensus in standards discussions, these drafts led to the adoption of a range of new features.
HTML 3.0
HTML 3.0 is a set of extensions to the HTML hypertext markup format. Like HTML 2.0, it is based on the Standard Generalized Markup Language (SGML). Unlike conventional desktop publishing, many details of how documents are laid out are left to the capabilities of individual browsers or reader preferences, rather than being completely specified by authors. This allows documents to be viewed on a very wide range of equipment. HTML 3.0 supports text flow around floating figures. Other major additions include fill-out forms, tables and mathematical equations, and features for greater control of layout.
Fill-out forms may include a range of input controls including checkboxes, radio buttons, single and multiline text fields and selection menus. Client side handling of constraints is possible via simple scripts linked to the form. Tables are built up from header or data cells, and you can merge cells for more complex layouts. The efforts of the World Wide Web Consortium's HTML Working Group to codify common practice in 1996 resulted in HTML 3.2
HTML 4.0
HTML 4 extends HTML with mechanisms for style sheets, scripting, frames, embedding objects, improved support for right to left and mixed direction text, richer tables, and enhancements to forms, offering improved accessibility for people with disabilities.
The section below describes how the 24 December 1999 version of the HTML 4.01 specification differs from the 24 April 1998 version of the HTML 4.0 specification.
New style sheets for the document based on W3C technical report styles.
Added a short table of contents.
Updated the copyright.
Fixed document scripts to remove markup causing crashes on some browsers.
Thanks to Shane McCarron added to the acknowledgments.
In section 1.4, removed copyright details and refer to W3C site instead.
References to the document character set are all ISO 10646 (and one time to UNICODE to signal equivalence). References to UNICODE refer only to the bidirectionality algorithm.
Examples now use dated FPIs.
HTML 5.0
This specification is limited to providing a semantic-level markup language and associated semantic-level scripting APIs for authoring accessible pages on the Web ranging from static documents to dynamic applications. This specification represents a new version of HTML4 and XHTML1, along with a new version of the associated DOM2 HTML API. Migration from HTML4 or XHTML1 to the format and APIs described in this specification should in most cases be straightforward, as care has been taken to ensure that backwards-compatibility is retained. A HTML5 browser should be flexible in handling incorrect syntax, in contrast to XHTML, where the browser must refuse to render a document at all even if there is just one illegal character or missing close tag. HTML5 is designed such that old HTML 4 browsers can safely ignore new HTML5 constructs. In contrast to HTML4, the HTML5 specification gives detailed rules for parsing, with the intent that different compliant browsers will produce the same result in the case of incorrect syntax. HTML5 introduces new ways of inserting sound and video in web pages with the
References
HTML 5: A vocabulary and associated APIs for HTML and XHTML. W3C Working Draft 22 January 2008.
