With XML’s ability to allow customized tagging systems, it is not surprising it is finding a wide variety of applications. Many XML languages are so specific that they will serve only a particular Intranet of a single business. Other XML technologies might serve a specfic community, as the Chemical Markup Language serves the scientific community but is of limited interest to most publishers.
The World Wide Web Consortium monitors other XML applications that have a greater impact on how media is presented over the Web, thus changing the Web’s capabilities. Two such applications are used for the synchronized multimedia presentations and a method for describing vector-based graphics in Web pages.
SMIL (Synchronized Multimedia Integration Language) is a language for combining audio, video, text, and graphics in a precise, synchronized fashion. The SMIL 1.0 specification, released in June, 1998, is one of the first XML-based DTDs proposed by the W3C.
The SMIL file (using tags that follow the XML syntax) instructs the client to retrieve media elements that reside on the server as standalone files. The advantages of SMIL include the ability to:
Add hyperlinks in a time-based presentation
Integrate media elements from more than one server
Reuse media elements in multiple presentations
Allow users to choose the media tracks they prefer, for example, based on connection speed or language preferences
The SMIL DTD ...