Snowlog lets you browse your web server's access log files. It does not generate static HTML status reports but instead shows you all accesses in a list that you can filter, sort and search easily.
disktool is an XView based GUI program,that monitors one or more filesystems and alerts the user when afilesystem has reached a critical threshold of available space.
System Health Monitor is a handy python program that will setup your system to generate RRD Graphs of network interface traffic, system load, memory usage, disk space and inode usage and running processes.
KBMon is a bandwidth-monitor for local network devices. On three different panels you can watch the speed of the transfered and the received data, and you can see the speed of the total data on the choosen interface.
EPAN is a protocol analyzer for ethernet networks. The program allows you to display the received frames either in an overview mode or in a frame detail mode.