Google announced an open-source effort to improve the real-time notification capabilities of feed syndication:
Real-Time Product Launch Recap - Digital Life Blog - InformationWeek
Pubsubhubbub - This one comes from Google (NSDQ: GOOG) and is very technical but the basic idea is any RSS feed using FeedBurner will now be updated nearly instantly whereas previously there was a delay in feed updating. It's built on the "pubsub" protocol and a variety of open-source clients have been created to allow applications that need feed data to receive it in a near real-time capacity. Google has created a wiki to discuss the Pubsubhubbub release.
Here’s the video from PubSubHub’s demo at the Real-Time event:
pubsubhubbub - Google Code
A simple, open, server-to-server web-hook-based pubsub (publish/subscribe) protocol as an extension to Atom.
Parties (servers) speaking the PubSubHubbub protocol can get near-instant notifications (via webhook callbacks) when a topic (Atom URL) they're interested in is updated.
The protocol in a nutshell is as follows:
- An Atom URL (a "topic") declares its Hub server(s) in its Atom XML file, via <link rel="hub" ...>. The hub(s) can be run by the publisher of the Atom, or can be a community hub that anybody can use. (RssFeeds are also supported!)
- A subscriber (a server that's interested in a topic), initially fetches the Atom URL as normal. If the Atom file declares its hubs, the subscriber can then avoid lame, repeated polling of the URL and can instead register with the feed's hub(s) and subscribe to updates.
- The subscriber subscribes to the Topic URL from the Topic URL's declared Hub(s).
- When the Publisher next updates the Topic URL, the publisher software pings the Hub(s) saying that there's an update.
- The hub efficiently fetches the published feed and multicasts the new/changed content out to all registered subscribers.
To bootstrap this, we've provided an open source reference implementation of the hub (the hard part of the protocol) that runs on Google App Engine, and is open for anybody to use.