[idupree]

Historical note: Launchd might have caught on if Apple had open-sourced it sooner.

The author of the Upstart init system, Scott James Remnant, wrote in 2006,

"How does [Upstart] differ from launchd?

launchd is the replacement init system used in MacOS X developed as an “Open Source” project by Apple. For much of its life so far, the licence has actually been entirely non-free and thus it has only become recently interesting with the licence change.

[...]

Had the licence been sufficiently free at the point we began development of our own system, we would probably have extended launchd rather than implement our own. At the point Apple changed the licence, our own system was already more suitable for our purposes."

http://netsplit.com/2006/08/26/upstart-in-universe/