SMIL 2.0: XML for Web multimedia

On 7 August 2001, the World Wide Web Consortium (W3C) released version 2.0 of Synchronized Multimedia Integration Language, or SMIL. Three years ago, SMIL 1.0 introduced a basic foundation for Web multimedia and it quickly gained widespread use. With a specification document about 15 times as large as version 1.0, SMIL 2.0 builds on this foundation and marks an enormous step forward in multimedia functionality. Although Web multimedia has long been obtainable with proprietary formats or Java programs, it's been largely inaccessible to most Web authors and isolated from the Web's technical framework. SMIL's HTML-like syntax aims to do for multimedia what HTML did for hypertext: bring it into every living room, with an easy-to-author descriptive format that works with readily available cross-platform players. SMIL lets authors create simple multimedia simply and add, more complex behavior incrementally. But SMIL isn't just HTML-like, it's XML, which makes it part of the W3C's family of XML-related standards including scalable vector graphics (SVG), cascading style sheets (CSS), XPointer, XSLT, namespaces, and XHTML. SMIL's features fall into five categories: media content, layout, timing, linking, and adaptivity. The latter brings altogether new features to the Web, letting authors adapt content to different market groups, user abilities, system configurations, and runtime system delays. The article covers each feature category and its basic constructs using a simple SMIL presentation built with the SMIL 2.0 Language Profile, which is the flagship SMIL-defined language for multimedia browsers.