System V style init programs by Miquel van Smoorenburg that control the
booting and shutdown of your system. These support a number of system
runlevels, each one associated with a specific set of utilities. For
example, the normal system runlevel is 3, which starts a getty on
virtual consoles tty1-tty6. Runlevel 5 starts xdm. Runlevel 0 shuts
down the system. See the individual man pages for inittab, initscript,
halt, init, powerd, reboot, runlevel, shutdown, and telinit for
more information.