In this recent post to his blog Padraic Brady starts his look at the Pubsubhubbub protocol (PuSH), how it compares to rssCloud and how to get started using it.

This article explores both of these sides ([the Publisher in Part 1 and] the Subscriber in Part 2), and introduces the basic code to get each working. The article also opens with a general introduction to this new protocol which you will definitely be hearing more about (especially if you run a blog) and contrasts it to its nearest rival, rssCloud.

He talks about the differences between it and the rssCloud functionality and gives an example of its use with the Zend_Feed_Pubsubhubbub Zend Framework component. His sample shows how to set up a publisher andn define topic and hub URLs for the service to use.