New HTML standard XHTML approved

 Geneva 26 Feb 00 The World Wide Web Consortium has approved a new standard XHTML. XHTML is the well-known HTML 4.0 used on the Internet today, but then reformulated in XML. XHTML documents have to conform to somewhat stricter rules than HTML documents. The advantage is that XHTML can be used in a wide range of applications, ranging from small mobile devices that use a mini browser, for instance for telemedical applications over long distance, to exchanging information between large scientific datasets that are to be processed by supercomputers.

XHTML1.0: The Extensible HyperText Markup Language is reformulation of HTML 4 in XML 1.0. The most important differences are that all tags have to be closed, all attributes have to be quoted, and XHTML is case sensitive. Not all tag have to be closed in HTML. For instance, a paragraph has an opening tag <p> and a closing tag </p>, but a break has not: <br> is enough. In XHTML the break-tag also has to be closed. Which is formulated as <br> </br> or abbreviated to <br/>. Attributes in HTML do not have to be enclosed in quotes, in XHTML they must. So the correct HTML <img src=picture.gif> has to be changed to <img scr="picture.gif">. In XHTML all tags have to be written in lower case. HTML was case-insensitive

What is the use of making live more difficult for peolple who write HTML? In fact, it is not really that difficult. One gets used to it very fast. On the other hand, most HTML is generated by computer programmes anyway, which do not care what they have to read or write. Computer programmers do care, of course, and it is for them that life becomes easier. They know what to expect from an XHTML document and do not have to implement computer code for all kinds of different situations that do not really add to a better understanding of the document structure or content: a paragraph is a paragraph, whether you write the tag in upper or lower case.

XHTML has more advantages:

  • XHTML documents are XML conforming. As such, they are readily viewed, edited, and validated with standard XML tools.
  • XHTML documents can be written to operate as well or better than they did before in existing HTML 4-conforming user agents as well as in new, XHTML 1.0 conforming user agents.
  • XHTML documents can use applications (e.g. scripts and applets) that rely upon either the HTML Document Object Model or the XML Document Object Model [DOM].

XHTML is modular. There is a base set with extensions. The base set can be used for instance for mobile communication to a device that only can operate a small browser. It could for instance be used to transmit and display medical data to a mobile device from a physician in a remote area .

Full XHTML can be used for instance when you have to transmit large data sets of complex data, for instance to do some text based data mining activities on a cluster supercomputer. In ad hoc situations it can be useful to rely on a standard exchange format based on XHTML.

The XHTML standard can be found at: www.w3.org/TR/xhtml1/

 

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