Systime tells you how much CPU time running a program uses. It is like the classic "time" command, except that "time" only tells the CPU time used by the immediate process, whereas "systime" includes other processes that serve the main process, such as the X server and kernel memory management processes. Systime reports all the CPU time used on the entire system while the subject program was running. It uses Linux's /proc filesystem.
EmSniff is an application that helps you to capture network packets. It differs from TCPDump in that it runs as a service instead of an application. This makes it possible to capture packets in the background. This can help applications like Wireshark to be more secure since they don't have to run with root privileges anymore. They only have to connect to the EmSniff server via libemsniff.
rstatus is a package containing rwho, ruptime and rwhod. Features include unlimited number of hosts on the network, disable broadcast (listen, do not send), directed send to hosts in another network and all kinds of sorted output. It has internationalisation support for Dutch and English.