What is "superfeedr"

Superfeedr is a feed API built on PubSubHubbub which is sometimes referred to as PuSH. It transforms a variety of feeds into standardized RSS, Atom or JSON format and distributes (or "pushes" them) them via PubSubHubbub or XMPP. This allows subscribers to receive notifications of new or updated content from their feeds, and publishers to send those notifications.