Just a quick note for those who need but can’t find the open source OSX system monitoring tool MenuMeters, which got lost in the OSX 10.11 upgrade.
Go to: MenuMeters for OS X El Capitan 10.11
It works. It is a simple port and the changes are well explained by the author. There is an install quirk that the first time you double-click on the program that it won’t install. Close the Preferences Application. Double-click on the menumeters preference pane again and it will install.