Zend Developer Zone have a posted a new tutorial on how to create an AJAX Chat application using the Zend Framework —”This tutorial is a step by step introduction to creating a lightweight chat application using XML as a storage medium. As personal motivation, I develop PHP games as a hobby. In pursuit of that hobby I've found that offering a flat threadless forum in such games tends to result in heavy usage as players attempt to use it as a chat room. The reason is that even with the advent of irc and instant messengers, users continue see an alternative web based solution as attractive for a number of reasons whether its limited access to instant messengers through a corporate proxy or simply for convenience sake.”
Continue for more info....

ajaxmagazine

Zend Framework, Zend Developer Zone, Chat Tutorial