2.4 Versions of HTML

HTML is an evolving language, and each new version is given a number. The first definitive version was HTML 2.0 -- this had most of the elements we know and love, but was missing some of the Netscape/Microsoft extensions, and did not support tables, or ALIGN attributes.

HTML 3 (late 1995) was an ambitious effort on the part of Dave Raggett to upgrade the features and utility of HTML. However, it was never completed or implemented, although many features were integrated in the next "official" version of HTML, known as HTML 3.2.

HTML 3.2 was the next official version, integrating support for TABLES, image, heading and other element ALIGN attributes, and a few other finicky details. HTML 3.2 is the current "universal" dialect -- essentially all browsers understand HTML 3.2. IT was, however, missing some of the Netscape/Microsoft extensions, such as FRAMEs, EMBED and APPLET. Support for these (after a fashion) came in HTML 4.0

HTML 4.01 is the current official standard. It includes support for most of the proprietary extensions, plus support for extra features (Internationalized documents, support for Cascading Style Sheets, extra TABLE, FORM, and JavaScript enhancements), that are not universally supported. Some of these enhancements are not discussed in these online notes. They are discussed in detail in The HTML 4.0 Sourcebook, available in most bookstores.

For more details about the various versions of HTML, you are also referred to the bibliography, which contains references to the various specifications, and to my online resource that defines the structural rules of the different HTML variants, found at the URL http://www.utoronto.ca/webdocs/HTMLdocs/HTML_Spec/html.html documents.

However, the evolution of HTML has now ceased -- HTML 4.01 is the last version of HTML. For the future, HTML is being replaced by a new language, called XHTML -- for the eXtensible HyperText Markup Language. The differences are actually small, but important, as described on the next section.

However, HTML and XHTML are very similar, so the things you learn in this tutorial will still be useful. My newer book, The XHTML 1.0 Language and Design Sourcebook, explains in details these differences and how to use the new XHTML language. On the other hand, Section 2.5 of this tutorial covers the most important differences, and costs a whole lot less!