On the IBM developerWorks site there's a recent tutorial about using PHP and Javascript with the XMPP to create a small web-based notification tool (called Pingstream).

Real-time web applications are networked applications, with web-based user interfaces, that display Internet information as soon as it's published. Examples include social news aggregators and monitoring tools that continually update themselves with data from an external source. In this tutorial, you will create Pingstream, a small notification tool that uses PHP and JavaScript to communicate over the Extensible Messaging and Presence Protocol (XMPP), a set of XML technologies designed to support presence and real-time-communications functionality.

You'll need to already have the usual software installed - PHP, Apache and MySQL - as well as a few others: Openfire, jQuery, Strophe, XMPPHP and LastRSS. They introduce some of the concepts behind real-time messaging, the XAMPP protocol and, of course the code to show how to create their service.

On his blog today Abhinav Singh has an interesting post describing how to use PHP and XMPP (the Extensible Messaging and Presence Protocol) to get real-time notifications of the status of your servers and applications via instant messenger.

There are several open and closed source softwares in the market which can generate almost real time notifications for you. Most famous one being Nagios. In this blog post I will discuss, how to generate real time system notifications using PHP and XMPP. Specifically, I will present sample script using Jaxl (Jabber XMPP Client Library) for generating real time system load notifications, which can be received using any Instant Messengers.

The code for a class that uses and extends the Jaxl library is included. It sends the messages via Jabber after grabbing the contents of the "/proc/loadavg" file on the local system. You'll need to check out the latest Jaxl source and create a configuration file with your IM information, but that's about it. The rest is handled by the script - you can see an example here.