Alternatives to apt-get?

You want Homebrew <https://brew.sh>

Homebrew does have a Linux implementation as well 😁

Older macOS package MacPorts <https://www.macports.org> and Fink <https://www.finkproject.org>, but these days Homebrew is the defacto standard for macOS and when you see web pages that suggest you install this, that or the other package, they will most likely give you a "brew install xyz" command.

As has been mentioned macOS is Carnegie Mellon's MACH micro-kernel and the OpenBSD kernel APIs along with many of the OpenBSD command line utilities. But there are a host of other open source (NON-GPLv3) commands and utilities, as well as many Apple developed commands. The closest similar operating system using a MACH/BSD implementation would be the Digital Equipment Corporation's DIGITAL UNIX, which was the MACH micro-kernel and BSD kernel APIs along with BSD commands (BSD came from the University of California, Berkeley campus, and stands for Berkeley Standard Distribution).

UNIX™ originated in Bel Labs (part of the original AT&T; not the current MCI that acquired AT&T and took the name).

Linux (including Debian) is an independently developed kernel with most of the core UNIX™ and BSD kernel APIs. Commands and utilities from a host of open source projects.

Here is an operating system family tree. The first section is just Unix derivatives, and each and everyone of them most likely has some differences in how you interact with it.

https://eylenburg.github.io/os_familytree.htm

Unix/Linux packages managers come in all flavors, none of which run on macOS. Here is a Wikipedia article on package managers

https://en.wikipedia.org/wiki/List_of_software_package_management_systems

Bottom line, ALL Unix/Linux systems look the same, except where they are different, and every implementation is DIFFERENT!

Indeed Homebrew is a (popular) package management system for macOS (and Linux), that is maintained and valid.

Installation - Homebrew documentation

They do suggest to switch from zsh to bash for Homebrew installation itself.

chsh -s /bin/bash

or

exec bash

Linux and Unix are different in many ways, and both Linux and Unix distros can and do differ among themselves too.

What is actually part of Unix—see the Open Group specs, as well as the IEEE POSIX specs, and those two can diverge in places—is usually quite consistent. Beyond that, not so much.

Linux is a kernel, and Linux userlands can and do differ across distros. Widely. For instance, the nix package manager, which avoids many of the issues with conflicting dependencies.

XNU is a combination of Mach and BSD with other bits, and most of userland is a mix of BSD and Apple bits.

Here, yes, Homebrew is typical for installing the tools not provided by Apple, and there are other package managers.

perfectreign wrote:

I know Mac OSX is a Unix-derived operating system.

It isn't. The BSD layer is just slapped on top, attached with duct tape and twine.

As such, I expected I would be able to open a terminal, and download some packages using apt-get, like on Debian.

You can always ask the developers of apt to provide macOS support. I doubt they would do that. They don't even support other distributions of Linux.

So.... what are some good CLI package installers these days? I found a thread from six years ago referencing home brew. Is that still valid?

Good? You require the package installer to be good? How come you set such a high quality standard for Mac package installers that even Linux package managers can't meet?

Homebrew not only still exists, it is now the de-facto package manager for macOS. Whether it is any good or not is something I can't answer. On Linux, I really don't have a choice. I have to use apt or whatever a particular version of Linux happens to support. If I'm lucky, it works that day. But at least on a Mac, I don't have to use them.