The free Munin monitoring software, which is written in the Perl programming language, is used to monitor computer systems and ensure their proper function. A central computer collects the performance data of the systems in the network and makes this available in the integrated web interface. Munin uses an RRD database to store the performance data. Munin supports all popular Unix and Linux platforms. The software should theoretically be able to run on all platforms to which Perl has been ported. Munin is flexibly extensible via its plugin system.