Conky is a free, light-weight system monitor for X, that displays any information on your desktop. Conky can display just about anything, either on your root desktop or in its own window by using scripts and other external programs. Conky has more than 250 built in objects, including support for a plethora of OS stats Conky can display this info either as text, or using simple progress bars and graph widgets, with different fonts and colours.Internet is full of examples as well as a wiki page
Below the system monitoring I created based on my needs.
Many examples in the following pages :