I'm sure that if you ask 10 maqueros about what launchd is, the most likely answer is that the majority who don't know about it or who have seen it hanging around the Activity Monitor, but very little more. But launchd is very important, vital, basic:
Initially released with Tiger, was the main culprit for the performance increase in system startup and its maintenance, and it is that launchd allows tasks or processes to be launched in these events:
- A configuration file is loaded
- It's been a while
- It has been programmed in time
- A program ended
- A network connection occurred
- A file was modified
- A directory was modified
In short, you can imagine that it is a basic part of Mac OS X from 2005 to today, and that it will continue to be unless Apple surprises with Mac OS X 10.7.