phubb

From IndieWeb

phubb is an open source standalone WebSub server written in PHP by Christian Weiske.

Works good enough for User:cweiske.de and implements the complete spec.

Code
http://git.cweiske.de/phubb.git/
http://github.com/cweiske/phubb
Public instance
http://phubb.cweiske.de/hub.php
You can test sending out notifications to your own reader via http://push-tester.cweiske.de/

See Also