Simple Update Protocol
Simple Update Protocol, or SUP, is a protocol developed by FriendFeed to simplify and speed up RSS and Atom. A few websites supported SUP for a while, meaning that updates from their services appeared in FriendFeed within seconds, until support was dropped, and eventually FriendFeed itself shutdown 2015-04-09. These sites include Disqus, Identi.ca, reddit.Brightkite
supported SUP but was itself shutdown in April 2012.YouTube
supported SUP according to , yet as that reference says "The YouTube Data API has been officially deprecated as of March 4, 2014."
via PubSubHubbub instead and no longer has SUP section.
