gisdnload is an ISDN load meter for Linux running as a Gnome applet. The display supports autoranging and changes its background color depending on whether you are online or offline.
Benson Distributed Monitoring System is an automated messaging and monitoring system designed to ease the life of a network, system,and database administrator.
RFC is a set of scripts that aims to help system-Administrators run a filesystem-checker (like tripwire, aide and so on...) from a "master-node" to several "slave-nodes" using ssh, scp, sudo and few other common shell commands.
QDU is a Graphical Disk Usage. Its histogram display lets you know very easily which directories and files are using up the disk space. You can delete, rename and move files.
sysfence is a resource monitoring tool designed for Linux machines. While running as daemon it checks resource levels and makes desired action if some values exceed safety limits.