W3C's EXI (Efficient XML Interchange) standard offers a compact representation of XML information; XML has served as a mechanism for exchange of data on the Web and elsewhere. "[EXI is] an optimization of the XML exchange," said John Schneider, editor of the EXI specification and CTO of AgileDelta.

The company's technology has provided a basis for EXI, he said. EXI reduces demands for network utilization, processing power, and energy when processing XML. Support is anticipated on software platforms like Java and Microsoft .Net. EXI solutions already exist from companies like AgileDelta, with its Efficient XML product line. Work already is going on to support EXI in development toolkits, W3C officials said.

"Even though [XML is] used everywhere, it's not used in some places because [of] constraints like giant documents or battery consumption or limited bandwidth," said Liam Quin, XML activity lead at W3C. Use cases for EXI, in addition to wireless phone applications, include sensor networks, cameras, automobiles, real-time trading systems, and other scenarios.

The standard results from a W3C effort to combat fragmentation in the space, in which application-specific approaches proliferated for a more efficient form of XML. The first draft of what is now EXI was released by W3C in 2007. W3C officials anticipate EXI could even displace XML at some user sites.