launchd Mastery: The Real init System of macOS

Every process on macOS starts here. From the first kext loaded at boot to the last login item registered when a user opens a session, launchd is the supervisor — a single daemon that replaced init, cron, and xinetd in one stroke and has remained the anchor of the platform for two decades.

This book walks launchd from the domain model down to the byte-level plist format. It covers how jobs are boots...