From adesklets.sourceforge.net:
adesklets is an interactive Imlib2 console for the X Window System. It provides to scripted languages a clean and simple way to write great looking, mildly interactive desktop integrated graphic applets (aka "desklets").

However, in September the 8th, 2010, the adesklets project announced it was officially dead.
I developed two applets for adeskelets which I'll keep archived here.

DigitalMon 0.0.1
Digital Display for both CPU and GPU (Nvidia) showing temperature and frequency.
CoreMon 0.0.1
A lightweight graph to display each CPU core usage.