SMIL 
Synchronized Multimedia Integration Language 
A programming language, based on HTML, that was proposed by the World Wide Web Consortium (W3C) in 1998. SMIL (pronounced "smile") allows Web developers to synchronize multiple media types to create a unified effect even over low-bandwidth connections. With SMIL, a Web developer can create separate audio, video, and still image files, send them to a computer separately so that they travel the Net more efficiently, and ensure that they all play back in sync to create the effect that he or she intended.