Is the source code of the application loading process is open?
where I can find it?
I want to understand better (in bits and bytes) what exactly happens from the moment users double click an app till the moment it's actually running on the latest macOS.
Can someone please refer me to the appropriate source code?
Best Answer
Private and Proprietary to Apple
Unfortunately no-one here will be able to show you this code, the macOS Finder is not open source. Only a portion of underlying operating system is available as open source.
Launch Services
The Launch Services framework is responsible for launching graphical applications. See the Launch Services Programming Guide for an overview.
Fundamentals
macOS's core, Darwin, is derived from FreeBSD. If you want to learn about the fundamentals of launching a new process, study today's FreeBSD code.
Fork
You will also want to fully understand
fork
and how processes are created in UNIX like environments.Fork (system call), Wikipedia: