conky

Conky is a free, light-weight system monitor for X, that displays any kind of information on your desktop. Conky is free software and runs in X on Linux and BSD. Originally a fork of Torsmo, Conky's torsmo-based code is BSD licensed. New code in Conky has been licensed under GPL 3.0. Since its inception, Conky has changed significantly from its predecessor, while maintaining simplicity and configurability. Conky can display just about anything, either on your root desktop, in its own window. Not only does Conky have many built-in objects, it can also display just about any piece of information by using scripts and other external programs. A plethora of OS stats (uname, uptime, CPU usage, mem usage, disk usage, "top" like process stats, and network monitoring, just to name a few). Conky can display information either as text, or using simple progress bars and graph widgets, with different fonts and colours.