Bubblemon is a dockapp for Blackbox, Window Maker, Afterstep and
Enlightenment. It displays CPU and memory load as bubbles in a jar of
water.

Bubblemon has 2 additional screen available - memory and load average.
To see the load average screen move the mouse into the window. To see
the memory screen hold the shift key before moving the mouse into the
window. Bubblemon fades from one display to the next, click the right
mouse button in the window to lock the fading halfway between the
displays.