Ajax_chat is a project mainly written in JAVASCRIPT and PHP, it's free.
Yet another Ajax chat web app written in old school PHP.
INSTALL
First install Mysql and Apache with the mod_php and the Mysql extension. Then run these bash commands using whatever paths make sense for your Apache and Mysql installs.
export AJAX_CHAT_HOME=/path/to/ajax_chat
sudo -E bash -c "echo \"Include $AJAX_CHAT_HOME/apache_includes/local.httpd.conf\" >> /etc/apache2/httpd.conf"
sudo -E ln -s $AJAX_CHAT_HOME /var/www/ajaxchat.brenttheisen.com
sudo -E apachectl restart
sudo bash -c 'echo "127.0.0.1 local.ajaxchat.brenttheisen.com" >> /etc/hosts'
mysql < $AJAX_CHAT_HOME/ajax_chat.sql