WWW6: eXtended Markup Language (XML)
the eXtended Markup Language (XML) is an alternative to the existing HTML to write documents that can be easily accessed over the Internet. XML is a subset of SGML. the term extendable refers to the fact, that an author can define his or her own tags and attributes. the limited set of tags in HTML has become one of its major problems. various vendors introduced new tags either in response to requests from the authors or simply to get an advantage over its competitors. this led to what became known as the "browser war". HTML V3.2 tried to address this problem by basically including all commonly used tags in the new standard.
another problem with HTML is the intermingling of contents and presentation. recently, this problem became addressed by the introduction of Cascading Style Sheets (CSS)
XML is a new approach to the same issues. some of the main features are:
XML linking elements are defined using the XML-LINK attribute. links are much more than just a pointer to another document, or maybe a pointer to a pre-defined position in such a document.
a link has one of the following values:
an author may also apply various policies to links. the SHOW attribute defines how the referred document shall be processed, the ACTUATE attributes defines when it shall be processed.
the SHOW attribute may take one of the following values:
the ACTUATE attribute may take one of the following values:
the combination of SHOW = "EMBED" and ACTUATE = "AUTO" provides a means to include one or more portions of text into a document, a feature that is missed by many authors in the current HTML standard.
in addition, XML provides means to access basically any character in any document without the need of having access to the referred document. it allows expressions to locate a particular position in a document such as "second chapter, third paragraph, forth occurrence of xyz".
see working drafts available from the W3C:
to the WWW6 trip report main document