The Multi Router Traffic Grapher (MRTG) is a tool to monitor the traffic
load on network-links. MRTG generates HTML pages containing PNG images which
provide a LIVE visual representation of this traffic. Check

WWW: https://oss.oetiker.ch/mrtg/

for an example. MRTG is based on Perl and C and works under UNIX and Windows
NT.

MRTG is being successfully used on many sites around the net.