Launchd

launchd is a unified, open-source service management framework for starting, stopping and managing daemons, applications, processes, and scripts. Written and designed by Dave Zarzycki at Apple, it was introduced with Mac OS X Tiger and is licensed under the Apache License.

The launchd daemon is essentially a replacement for:

• init
• rc
• init.d script
• rc.d script
• SystemStarter (Mac OS X)
• inetd
• xinetd
• atd
• crond
• watchdogd

Apple has stated that it intends to eliminate all of the aforementioned services in favor of launchd.

For Mac OS X v10.4 Apple moved most of the processes handled by the previously mentioned daemons to launchd. By consolidating all the launch services into one program, launchd significantly shortens boot time on slow computers.