HTML has gone through four major standards, including the latest 4.01. Inaddition to the HTML standards, Cascading Style Sheets and XML have also provided valuable contributions to Web standards.
HTML 1.0 was never formally specified by the W3C because the W3C came along too late. HTML 1.0 was the original specification Mosaic 1.0 used, and it supported few elements. What you couldn’t do on a page is more interesting than what you could do. You couldn’t set the background color or background image of the page. There were no tables or frames. You couldn’t dictate the font. All inline images had to be GIFs; JPEGs were used for out-of-line images. And there were no forms.Every page looked pretty much the same: gray background and Times Roman font.Links were indicated in blue until you’d visited them, and then they were red.Because scanners and image-manipulation software weren’t as available then, the image limitation wasn’t a huge problem. HTML 1.0 was only implemented in Mosaicand Lynx (a text-only browser that runs under UNIX).
Huge strides forward were made between HTML 1.0 and HTML 2.0. An HTML 1.1actually did exist, created by Netscape to support what its first browser could do.Because only Netscape and Mosaic were available at the time (both written underthe leadership of Marc Andreesen), browser makers were in the habit of adding theirown new features and creating names for HTML elements to use those features.Between HTML 1.0 and HTML 2.0, the W3C also came into being, under theleadership of Tim Berners-Lee, founder of the Web. HTML 2.0 was a hugeimprovement over HTML 1.0. Background colors and images could be set. Formsbecame available with a limited set of fields, but nevertheless, for the first time,visitors to a Web page could submit information. Tables also became possible.
Why no 3.0? The W3C couldn’t get a speci?cation out in time for agreement by themembers. HTML 3.2 was vastly richer than HTML 2.0. It included support for stylesheets (CSS level 1). Even though CSS was supported in the 3.2 specification, the browser manufacturers didn’t support CSS well enough for a designer to make muchuse of it. HTML 3.2 expanded the number of attributes that enabled designers toncustomize the look of a page (exactly the opposite of HTML 4). HTML 3.2 didn’t include support for frames, but the browser makers implemented them anyway.
What does HTML 4.0 add? Not so much new elements—although those do exist—asa rethinking of the direction HTML is taking. Up until now, HTML has encouragedinterjecting presentation information into the page. HTML 4.0 now clearlydeprecates any uses of HTML that relate to forcing a browser to format an element acertain way. All formatting has been moved into the style sheets. With formatting information strewn throughout the pages, HTML 3.2 had reached a point wheremaintenance was expensive and dif?cult. This movement of presentation out of the document, once and for all, should facilitate the continued rapid growth of the Web.
HTML 4.01 is a minor revision of the HTML 4.0 standard. In addition to fixing errors identified since the inception of 4.0, HTML 4.01 also provides the basis for meanings of XHTML elements and attributes, reducing the size of the XHTML 1.0 specification.
Extensible HyperText Markup Language (XHTML) is the first specification for the HTML and XML cross-breed. XHTML was created to be the next generation of markup languages, infusing the standard of HTML with the extensibility of XML. It was designed to be used in XML-compliant environments, yet compatible with standard HTML 4.01 user agents.