GData - Google's new syndication protocol

"GData combines common XML-based syndication formats (Atom and RSS) with a feed-publishing system based on the Atom publishing protocol, plus some extensions for handling queries."

So GData is a new protocol, but "based on Atom 1.0 and RSS 2.0." Actually at first glance it seems to be a mix of RSS and APIs. It bears a bit of resemblance to the Atom syndication format, with its extensibility and publication protocol. But apparently GData does more than Atom:

"In various contexts, it's useful to be able to send a query to a server and receive a response containing a list of matching results. Neither Atom nor RSS provides a way to do that, but GData does."

When they talk about possible uses, it looks like Google is targeting its own increasingly integrated web apps:

"All sorts of services can provide GData feeds, from public services like blog feeds or news syndication feeds to personalized data like email or calendar events or task-list items."

It's an interesting development by Google and is sure to ruffle a few feathers in the RSS and Atom camps, both of which are sensitive and prickly at the best of times. More on this as I investigate.