Sadly defunct. But it was an AlgebraOfFeeds thang.

Some good commentry though.

TimOReilly historical analysis : http://radar.oreilly.com/archives/2007/02/pipesandfilte.html

AnilDash comment : https://anildash.com/2007/02/08/yahoo_pipes/ Very explicitly ties it with SocialSoftwareDevelopment

PipeDream seems to be a new version of it.