The Hypertext Markup Language (HTML) is the dominant language for web pages.
This is just a short overview page. See also:
- HTML links
- HTML5 (overview)
- HTML and XHTML elements and attributes, a tutorial that introduces the most important HTML and XHTML elements and attributes.
Popular finalized HTML versions
The version of HTML was created in 1991 in a documented called HTML Tags (retrieved 15:26, 1 September 2009 (UTC)) and included about 20 elements.
HTML 2.0 was published as RFC 1866 (november 1995), with some later additions, like RFC 2867 (forms), RFC 1942 (tables), RFC 1980 (client-side image maps). HTML 2.0 is rarely seen anymore...
Many web pages still use 3.2. It displays fine on all modern browsers, unless people use unofficial (non 3.2) extensions from that time. There can be CSS problems though, but if a browser detects HTML 3.2 if will fall into a "quirks" mode that can deal with it...
HTML 4 was first published in 1997 and then refined in december 1999 as HTML 4.01.
- HTML 4.01 (May 2001)
HTML 4.01 is the current HTML (not XHTML) specification, and there exist three variants:
- HTML 4.01 strict is a cleaned up version of HTML, i.e. does not contain styling functionalities that can be had through CSS stylesheets.
- HTML 4.01 transitional includes tags such as center, font and strike that were deprecated in HTML 4.01 strict
- HTML 1.0 Frameset includes framesets (excluded from HTML 4.01 strict).
- See also: XHTML
- XHTML 1.0 (jan 2000).
- XHTML 1.0 formulates HTML 4.01 in XML and includes some other minor changes. As for HTML 4.0, there existe three versions: transitional, strict, and frameset.
- XHTML 1.1 (May 2001) adds minor changes to XHTML 1.0 and is described in modular form. There only is a single version. However, its modular format allows to specify smaller sets of the language. XHTML 1.1 isn't as popular popular as XHTML 1.0, except for its mobile profiles.
HTML5 is a future standard. However, it is now adopted by many top sites since HTML5 includes many interesting new features. As of Jan 2014, probably over a third of all major sites use HTML5. This includes for example MediaWiki's (look at the source of this page or Wikipedia) or YouTube. In addition, HTML5 gains share on SmartPhones. Many native applications could be replaced by HTML5.
See our HTML5 overview.
For us, it is not clear what the successor of XHTML 1.1 will be. For certain, there will be an XML serialization (e.g. closed tags etc.) of HTML 5 and it's already mentioned as such in the draft. The big questions is whether true (extensible) XHTML 5 will exist.
Comments on the death of XHTML 2.0
See the Unofficial Q&A about the Discontinuation of the XHTML2 WG for more information
My two cents on the death of XHTML 2.0 (Daniel K. Schneider 13:12, 8 September 2009 (UTC)):
- Since web designers and managers (and they make up the majority of the guys in the standards committees and vendor management) don't have a clue about large documents, XTHML 2 never had a chance. I liked those (indeed) quite different XHTML 2.0 functions that added structure to documents. Fortunately the HTML5 standard also will include sectioning elements.
- To compensate for the "hey web pages are just menus + multimedia" or the slightly more sophisticated "hey HTML is just rendering, documents can be encoded in anything else" attitudes, we may see other plugins or browsers for displaying real content. E.g. have a look at all the e-book formats (and players). In addition, we may see more client-side XSLT to display document-centric formats such as DocBook or DITA. After all, IE 6 already did that perfectly well.
Finally, I can't explain why version declaration is removed in HTML5 and why namespace declaration isn't mandatory in the XHTML version. How then, could a browser detect HTML 6. In fact I don't know enough, I'll wait and see :) - Daniel K. Schneider 13:12, 8 September 2009 (UTC)-
It is important to define a document type with a document declaration on line one of the HTML document'. If you don't or do it badly then browser will fall into a "quirks mode" and your CSS may not work as intented.
Below is a list of the most important document declarations.
HTML 5 <!DOCTYPE html> HTML 4.01 Strict DTD: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> HTML 4.01 Transitional DTD: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/1999/REC-html401-19991224/loose.dtd"> HTML 4.01 Frameset DTD: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN" " http://www.w3.org/TR/1999/REC-html401-19991224/frameset.dtd"> HTML5 DTD: <!DOCTYPE html> XHTML 1.0 Strict DTD: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> XHTML 1.0 Transitional DTD: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> XHTML 1.0 Frameset DTD: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd"> XHTML 1.1 DTD: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
Less popular and dead versions
- HTML Tags (a CERN document of 1992)
- HTML 3.0 was an aborted attempt in 1995.
- HTML 4.0 (dec 1997). It was the first series of standards that distinguised between strict, transitional (deprrecated elements allowed) and frameset.
This version tried to introduce a more coherent document markup, e.g. through the use of sections (like in DocBook), but since Summer 2009 it is a dead project.