(via www.ubuntugeek.com)
Monitorix is a free, open source, lightweight system monitoring tool designed to monitorize as many services as possible. At this time it monitors from the CPU load and temperatures to the users using the system. Network devices activity, network services demand and even the devices’ interrupt activity are also monitored, and more.
The current status of any corporate server with Monitorix installed can be accessed via a web browser.