From what I can tell this is what it does in a nutshell?
Personal eventing provides a way for a Jabber/XMPP user to send updates or "events" to other users, who are typically contacts in the user's roster. An event can be anything that a user wants to make known to other people, such as those described in User Geolocation , User Mood , User Activity , and User Tune . While the XMPP Publish-Subscribe  extension ("pubsub") can be used to broadcast such events associated, the full pubsub protocol is often thought of as complicated and therefore has not been widely implemented.  To make publish-subscribe functionality more accessible (especially to instant messaging and presence applications that conform to XMPP IM ), this document defines a simplified subset of pubsub that can be followed by instant messaging client and server developers to more easily deploy personal eventing services across the Jabber/XMPP network. We label this subset "Personal Eventing Protocol" or PEP."
Is that pretty much how its used in openfire? Thanks in advance for any help.