FriendFeed Blog: Simple Update Protocol. FriendFeed infamously poll RSS feeds on the 43 services they support millions of times an hour in an effort to keep their content as real-time as possible. SUP is a new proposal by FriendFeed for a sort of “master feed” of changes to a site—instead of hitting the Flickr feed for each of their users they would just poll Flickr’s SUP feed every minute or so to find out who had uploaded a new photo, and only retrieve the RSS feed for those users.
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Really a great idea, I could use something like this for a client project I'm working on. The problem will (as always) be to get the various parties to implement such a feature.