transparency
http://hugo.pereira.free.fr/software/index.php?package=transparency

Transparency is a set of transparent applications:
 * a transparent calendar;
 * a transparent analog clock;
 * a transparent CPU load display for user, nice and system jobs, based on /proc/stat file;
 * a transparent display for memory and swap load, based on /proc/meminfo file;
 * a transparent display for network load, based on /proc/net/dev file;
 * a transparent display for disk load, based on /proc/stat, /proc/partitions and /dev informations;
 * a transparent display to monitor laptop's battery;
 * a transparent summary of all previous informations in text format;
 * a basic transparent image viewer, ImageView.