psDooM is a process monitor and manager for *nix systems. It could be considered a graphical interface to the 'ps', 'renice', and 'kill' commands. psDooM is based on XDoom, which is based on id Software's 'Doom'.
cstat is a tool to gather real-time statistics
from Cube and Cube engine 2 game servers and
output text, ANSI, and XML. Supported games are
Cube, Sauerbraten, AssaultCube, and Blood Frontier.
q3ctrl is an implementation of the Quake 3 Arena server communication protocol, running as a command line utility. It is handy for sending commands (or command scripts) to your dedicated server, or checking its status. It is also able to query the master servers.