It isn't actually as nice and tidy as it would seem because you do not have a direct separation between system configuration and application configuration.
It's a small, subtle detail that for many is less important today than it once was; however, if I have two FreeBSD systems of mostly equal versions and I want to migrate applications and/or users from one to the other, I know ALL I have to do is copy from /usr/local -- try that on your Ubuntu machine. Good luck separating the system-specific configurations from your user and application configurations.
I don't want that separation in a consistent and coherent system. User vs base is artificial. What I care about is the end result the overall system accomplishes and base vs non-base doesn't really factor into that. What does it matter to me if nginx is part of the base system or not? I need a web server. Arbitrarily choosing apache/httpd vs nginx to include as part of the base system is incidental complexity where I stand from.
> If you update your OS, do you also need to update nginx? No, because there's backwards ABI compatibility.
Only for minor versions. How is that different from any other package that promises ABI compatibility?
Why are FreeBSD OS components split up at a low granularity, so you can't install the stuff you want without the stuff you don't?
Why are there two separate sets of tools to update them and other packages?
edit: Why separate non-base packages from base packages on the filesystem, but not from each other? If the advantage of separating /usr/local is the ability to copy the non-base configuration/apps without the base stuff, wouldn't it be more useful to be able to copy any given individual package or set of packages? Or if that is possible already (by asking the package manager for a list of files or whatnot), wouldn't that obviate the need to separate base from non-base?
You're talking about kernel vs userland. That's not base vs non-base. The BSD distributions unintentionally muddy the waters by calling what is an equivalent of a linux distribution a base system and so lose out on the distinction you are drawing.
No, I'm talking about the Operating System vs. Applications.
Drawing the line at the kernel syscall ABI is arbitrary; no other major operating system other than Linux does so.
Consider how difficult it is to ship 3rd-party applications for Linux and all its myriad of distributions; the only thing you can truly rely on is the anemic syscall ABI provided by the kernel (vs. userland).
Hmm, I've never had any problems running something on ubuntu, debian, gentoo, redhat, etc. If it works on one then it works on all the others. If push comes to shove I just install the libraries and compile from source but this is a rare occurence and I've only have had to do that when I've relied on a version of Ruby or Python that has not come pre-packaged with the distribution.
So I don't really know what you're getting at. If you're not talking about kernel vs userland and you're talking instead about ABI compatibility then the ABI is even more stable and requires even less work to port any piece of software from one distribution to another.
This is an increasingly solved problem in the post-systemd world - /etc contains local configuration, system configuration is in /usr. We (CoreOS) support you doing mkfs on / in order to return to a default configuration built from the /usr config.
NeXt->Apple also avoided anything like systemd via a configuration system that supported inheritance across search domains (User, Local, Network, System):
Oh, there's certainly multiple ways to do this. My point is purely that this isn't an inherent Linux/*BSD thing - there are modern Linux distributions that have precisely this property.
This is something I actually like about systemd and firewalld, everything in /usr/lib/systemd/ and /usr/lib/firewalld should only be handled by your package manager, anything you customize yourself belongs in /etc/systemd/ and /etc/firewalld, and they will override the corresponding entries in the 'global' folders if you give them the same filename.
It's a small, subtle detail that for many is less important today than it once was; however, if I have two FreeBSD systems of mostly equal versions and I want to migrate applications and/or users from one to the other, I know ALL I have to do is copy from /usr/local -- try that on your Ubuntu machine. Good luck separating the system-specific configurations from your user and application configurations.