The notes here are essentially summaries of the SMIL Specification and tutorials available at the WWW3 consortium web site:
A SMIL document is a special kind of XML 1.0 document:
Extensible Markup Language (XML) is a human-readable, machine-understandable, general syntax for describing hierarchical data, applicable to a wide range of applications (databases, e-commerce, Java, web development, searching, etc.). XML is an ISO compliant subset of SGML (Standard Generalized Markup Language). XML is extensible because it is a metalanguage, which enables someone to write a Document Type Definition (DTD) like HTML 4.0 and define the rules of the language so the document can be interpreted by the document receiver. The purpose of XML is to provide an easy to use subset of SGML that allows for custom tags to be processed. Custom tags will enable the definition, transmission and interpretation of data structures between organizations.
Further information on XML may be found at: