Munin(Memory) is a networked resource monitoring tool.
Munin is programmed in Perl, need perl5 and some perl modules like cpan for inslallation.
The last stable version is Munin 2.0.20.
Full documentation: http://munin.readthedocs.org/en/latest/
For Redhat/CentOS users, there is only 1.x version of Munin at EPEL repository, the 2.x version of Munin, it’s need to compile and install from the source.
How to get the source: git clone git://github.com/munin-monitoring/munin or http://sourceforge.net/projects/munin/files/stable/