Synchronised Multimedia Integration Language defined by W3C. SMIL, pronounced `smile`, enables simple co-ordination of interactive multimedia content. For example, integrating audio, video, still images, text etc. SMIL is a markup language like XHTML and WML. MMS can use SMIL to integrate its various medium types and a mobile-optimised SMIL is under development by 3GPP.
... Found on http://www.encyclo.co.uk/visitor-contributions.php