WebMonitor.ie is a popular open-source webmonitoring and alerting engine. It includes an automated email alert system, and full uptime history and graphical uptime statistics. It is written in PHP and uses MySQL as its back end database (requires version 4 or above for both). Webmonitor is a lightweight webmonitoring and alerting tool written in PHP, using MySQL as its back end database. It is a great tool for adding monitoring functionality to your web site or building your custom web monitoring tool. Webmonitor is small, easy to set up and modify, and is used to monitor thousands of websites across the world. Webmonitor supports all standard PHP and MySql Verisons, but also includes a plethora of advanced features such as adjustments to user levels, adding splash pages etc. The sophisticated adminstration interface makes administering the system easy. The full list of WebMonitor features can be seen in the about section; also be sure to check out the screenshots .