This is a WebSub server. You can use it to instantly notify feed subscribers about updates.
To notify this hub that one of your sites changed, send a HTTP POST request to http://phubb.cweiske.de/hub.php:
$ curl -d hub.mode=publish -d "hub.url=http://blog.example.org/feed" http://phubb.cweiske.de/hub.php
This hub will then notify all subscribers about the update.
This hub supports additional notification modes.
If you do not know which of your pages did change - only that some of them did change - you can pass a wildcard URL (with *). phubb then checks all subscribed URLs that match the wildcard for changes and then notifies the subscribers:
hub.url=http://blog.example.org/*
To enable feed readers to detect that they can get updates via PubSubHubbub, you have to send two HTTP Link headers along with your files.
The first is a Link header pointing to this hub:
Link: <http://phubb.cweiske.de/hub.php>; rel="hub"
The second is a Link header containing the full URL of the site itself:
Link: <http://blog.example.org/feed>; rel="self"
Only if both HTTP headers are available, feed readers and other subscribers will be able to get updates via this hub.
You can show the number of feed subscribers with an image on your site. The URL is counter.php?topic=$url:
<img width="55" height="20" alt="Subscriber counter"
src="http://phubb.cweiske.de/counter.php?topic=http://example.org/feed" />
phubb is a WebSub server written by Christian Weiske and licensed under the AGPL v3 or later.
You can get the source code from git.cweiske.de/phubb.git or the mirror on Github.