[matthewsimon]

Sheesh, did you bother to read the linked document?

The "client" in pubsub registers a call-back URL with the server, and the server then POSTs new data to that URL.

No periodic polling required -- that's the whole point of this.

[iwwr]

Sorry, I was confused. I thought 'hubbub' was a drop-in replacement for RSS. Apparently, it's a meta-protocol built around RSS.