xmon
xmon is a small and lightweight graphical system performance monitor for Linux.
Downloads and Documentation
http://pubwww.fhzh.ch/~mgloor/xmon.html
jperfmeter
JPerfmeter is a simple performance statistics monitor designed in the style of perfmeter. It requires that the rpc.rstatd daemon be installed on the monitored system.
Downloads and Documentation
http://www.gps.uklinux.net/sar_plot/
slmon
SLmon is a tool for monitoring a system's performance. It displays results using a nice and easily readable text-based UI. It has the ability to monitor CPU load (SMP is supported), memory/filesystems usage, network interfaces, uptime, date and time, and the number of logged in users.
Downloads and Documentation
http://slmon.sourceforge.net/
