SYMM

W3C's SYMM has focused on the design of a new language for choreographing multimedia presentations where audio, video, text and graphics are combined in real-time. The language, SMIL is written as an XML application and is currently a W3C Recommendation. Simply put, it enables authors to specify what should be presented when, enabling them to control the precise time that a sentence is spoken and make it coincide with the display of a given image appearing on the screen.(Definition adapted from the original specification document)