NagVis is a visualization addon for the well known network managment system Nagios. NagVis can be used to visualize Nagios Data, e.g. to display IT processes like a mail system or a network infrastructure.
phpTrafMon is a set of scripts written in php. It shows in an attractive and user-friendly way the traffic in a local network and a share in it of every user. phpTrafMon requires MySQL, crontab and a popular IPFM program.