Instead of eureka I would say CONKY!
I have search for sys monitor tool for ubuntu.
Very simple, very stable with low load on CPU (~0.5%) and lots of configuration possibilities. There’s a Conky markup language for your configuration, but also you can write your monitors with python or awk.
Check is out at: http://conky.sourceforge.net/
“<...>Conky is a free, light-weight system monitor for X, that displays any information on your desktop. Conky is licensed under the GPL and runs on Linux and BSD.”
And some examples from the net to be clear what can be configured with this tool:
