Quote Originally Posted by dsr View Post
Some distros use entirely different init systems (e.g. Ubuntu, which uses something called Upstart).
Just FYI,
Upstart is an event-driven replacement for the init daemon
written by Scott James Remnant of Canonical (previously a Debian maintainer)

The original SysV and BSD init systems are very linear, and do not fair well with hot-pluggable devices, or other external system changes

Say you have /usr mounted via NFS
When the boot process hits the mounting of /usr, it could potentially take a little time
(If not done so already, got to initialise networking, get IP, etc.)

Upstart uses events to trigger init scripts, making the whole thing asynchronous, and therefore much more concurrent

You can read the original Ubuntu blueprint from 2006
https://wiki.ubuntu.com/ReplacementInit

Upstart is also, now, used on Fedora and Palm's WebOS