The init Daemon
The init daemon is the system and service manager for Linux. It is the first true process Linux starts when it boots and as such, has a PID of 1 and is the ancestor of all processes. The init daemon has been around since the early days of UNIX, and many people have worked to improve it. The first Linux init daemon was based on the UNIX System V init daemon and is referred to as SysVinit (System V init daemon).
Because SysVinit does not deal well with modern hardware, including hotplug devices, USB hard and flash drives, and network-mounted filesystems, Fedora/RHEL recently replaced it with the Upstart init daemon (http://upstart.ubuntu.com/ and http://upstart.ubuntu.com/wiki). Fedora 15 has moved past Upstart to systemd init daemon.
