[gh02t]

Lol no. On many levels. MacOS does implement separate daemons, but they're all very tightly integrated, communicating over a common protocol. The core components hardly run in isolation, nor are they interchangeable. You don't, for example, just replace launchd with some other init system. You don't just say "hey, screw Aqua I want to use something else." (You can run other WMs through X11, but only on top of Aqua) Darwin is a bit more BSD-like, but nobody actually uses Darwin without the rest of MacOS.

And seriously, systemd isn't one single daemon either. It's a collection of daemons running that communicate over a common protocol. It isn't all-or-nothing, either. Only a few of the daemons are considered "core" and the rest are optional. And, because they use a common documented protocol, even the core components can be replaced. You don't hear about alternatives because nobody has really written any, but it doesn't in any way prevent you from doing it.

I think the legitimate concerns about systemd are things like losing portability of stuff like Gnome to BSD and systemd's short history, but it isn't one giant monolith executable or anything like people say.

[teacup50]

> Lol no. On many levels. MacOS does implement separate daemons, but they're all very tightly integrated, communicating over a common protocol.

What common protocol? Mac OS X doesn't have dbus. It recently acquired XPC, but XPC is NOT a system bus -- it's simply an IPC library. It's neither required, nor universally used, nor is it terminally glued to the remainder of the OS.

> You don't, for example, just replace launchd with some other init system.

You don't? Says who? All launchd does is serve as an inetd/cron-esque daemon. The system daemons themselves continue to vend standard sockets and mach ports, and launchd itself does not pervade their externally vended interface.

> You don't just say "hey, screw Aqua I want to use something else."

Actually, you can. The display stack is driven by IOKit; XDarwin can run directly atop said stack.

Likewise, none of the "Mac-like" features that you want -- for example, automatic network configuration -- rely on any sort of centralized entity that pervades all daemons. There's a seperate system -- SystemConfiguration -- that provides that functionality, abstracted through a set of well-defined APIs and modular and distinct from the remainder of the system.

> * It's a collection of daemons running that communicate over a common protocol.*

Hence it's really rather monolithic, because to play in the systemd universe, everything has to conform to systemd's tightly coupled design.

[gh02t]

What you're describing is all quite similar to how systemd operates. Your definition of "monolithic" seems to be that the components communicate with each other. My definition is that the components are difficult to replace. Systemd makes it easier to replace components, because the requisite interfaces are clearly defined.

MacOS is quite tightly integrated, it's what Apple does. Darwin is a bit different, as it's much more BSD-ish; with that I agree. But MacOS is a lot of stuff on top of Darwin and replacing any part of that would require tons of very MacOS specific code to do. Apple most definitely does not intend for their users to be able to replace logind or Aqua or pretty much any core service.

Probably a better way to phrase it would be to consided how much effort it'd take to run Aqua on BSD. You'd have to port basically everything that is MacOS. To me, that is what a monolithic system means.