The World Wide Web Consortium (W3C) has produced a new spec for multimedia presentations on mobile phones.

Synchronized Multimedia Integration Language 2.1 (SMIL 2.1) is based on XML and provides enhanced visual layout such as background image tiling, and audio layout including fade-in and fade-out, according to the standards body.

The new spec also allows authors to predefine sets or parameters that may be referred to multiple times in a presentation and across presentations. Such reuse makes it easier to draft content and reduces the size of SMIL presentations, improving end performance.

SMIL 2.1 will have the greatest impact on MMS and mobile streaming, offered over high-speed, packet-switched 3G networks.