Google's Pubsubhubbub
scripting.com/stories/2009/07/10/googlesPubsubhubbub.html
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
It's got a weird name, and I found the spec somewhat hard to understand. But thanks to Brad Fitzpatrick and Brett Slatkin from the team at Google that implemented it, I now un...