SMIL: Synchronized multimedia integration language
The period from 1995 to 2010 can be considered to be networked multimedia's Golden Age: Many formats were defined that allowed content to be captured, stored, retrieved, and presented in a networked, distributed environment. The Golden Age happened because network infrastructures had enough bandwidth available to meet the presentation needs for intramedia synchronization, and content codecs were making even complex audio/video objects storable on network servers. This period marked the end of the CD-ROM era for multimedia content distribution. Unlike the relative simplicity of CD-ROM multimedia, where timing constraints were well-understood and pre-delivery content customization was relatively simple, the network multimedia era demanded new languages that would allow content to be defined as a collection of independent media components that needed to be located, fetched, synchronized, and presented on a large collection of user devices (under greatly varying network characteristics). One of the most ambitious projects to define an open and commonly available multimedia content integration language was W3C's SMIL. In a period of approximately ten years, SMIL grew from a simple synchronization language to a full content integration and scheduling facility for a wide range of Web documents. This chapter considers the timing and synchronization aspects of SMIL.