Monitorix
From James's Wiki
how to install on RPI
sudo apt-get install apache2 rrdtool perl libwww-perl libmailtools-perl libmime-lite-perl librrds-perl libdbi-perl libxml-simple-perl libhttp-server-simple-perl libconfig-general-perl libio-socket-ssl-perl
wget "http://www.monitorix.org/monitorix_3.10.0-izzy1_all.deb"
sudo dpkg -i monitorix_3.10.0-izzy1_all.deb
sudo apt --fix-broken install
