In September, the W3C will host a workshop on binary XML formats. Your first reaction may be the same as mine: what the heck is binary XML? Binary XML is an attempt to find a common format for communicating pre-parsed XML trees to reduce bandwidth and the time it takes to parse large XML documents. The audience is primarily embedded and similar applications, but of course, once the genie's out of the bottle, it will be used in all sorts of applications. The announcement lists several advantages:

• It would not be restricted to a single schema or vocabulary, and hence could be interoperable between vocabularies;
• It would not be restricted to a single application or hardware device, and hence could be interoperable between implementations;
• Improved network efficiency and reduced storage needs: compression techniques that make use of domain-specific knowledge often do better than more generic compression;
• Sending pre-parsed data could reduce the complexity of applications, and may facilitate creation of simpler internal data structures.
• Web Services may need more efficiency, and a pre-parsed binary transmission format may help people to continue to work with Web Services rather than to explore proprietary interfaces

The biggest disadvantage is that pre-parsed data does not conform to the view source principal that has served the Web so well. In that sense, pre-parsed data doesn't seem Restian.