A number of readers have noted Google's open sourcing of their internal data interchange format, called Protocol Buffers (here's the code and the doc). Google elevator statement for Protocol Buffers is "a language-neutral, platform-neutral, extensible way of serializing structured data for use in communications protocols, data storage, and more." It's the way data is formatted to move around inside of Google. Betanews spotlights some of Protocol Buffers' contrasts with XML and IDL, with which it is most comparable. Google's blogger claims, "And, yes, it is very fast — at least an order of magnitude faster than XML."