Short for Synchronized Multimedia Integration Language, SMIL is an XML (extensible markup language) that describes multimedia events and objects. It was proposed in 1999 by the W3C (World Wide Web Consortium), and can be used to define the appearance and animated characteristics of many different forms of audio and visual digital media.
As a markup language, SMIL has many similarities to HTML. Its main body of content is contained in a section, for instance. SMIL is used in the interface of many DVD players, and is used by Hulu as part of its video-on-demand interface. Software that supports SMIL includes QuickTime and RealPlayer.
SMIL files have the extension .smi or .smil.