tcsysmon is a dock app that monitors Mem/Swap/DiskIO/Uptime and displays blinky lights for your interrupts and page in/outs. Its goal is to display as many real-time system statistics as possible with a minimum of CPU usage. It includes MMX routines for faster updates on newer CPUs.
wmnetload is a network interface monitor dockapp for Window Maker. It is designed to fit well with dockapps like wmcpuload and wmmemmon. It tracks whether the interface is functioning and displays current network interface throughput, along with an auto-scaling graph of recent network activity (the graph separates upstream and downstream traffic load cleanly without resorting to colors).