This is a statement that is frequently made and it has always puzzled me. Yes, Windows has practically the whole of the desktop market, but who ever made money by hacking a desktop? Apart from creating DDOS swarms, there's not much you can do with hacked desktops. All the money is in hacking servers. That's where you get the lists of bank details and authentication tokens that people trade on the black web. It's also where you are most likely to clean up big with ransomeware, because companies can afford to pay much more than individuals. And all the servers run Linux.

Anyone who found out how to hack Linux easily would make much more out of it than he ever could by hacking Windows. So why do we never hear about it happening?

This is the description from the page pointed to by the URL provided by YesItsMe:

"An immutable distro ensures that the operating system's core remains unchanged. The root file system for an immutable distro remains read-only, making it possible to stay the same across multiple instances. Of course, you can change things if you would like to. But, the ability remains disabled by default."

Which I'm interpreting to mean that the read-only setting can be changed, after which "root" can change things.

Naturally there are reasons to have security, especially for an organization which, for various purposes, may well allow some sort of access to some of their systems, from the outside. I would expect that having a so called "Immutable distribution" is an attempt to minimize the number of programs which could be exploited to gain some degree of control of a system, from outside.

Booting from a CD or DVD is immutable. Booting from a read-only ISO image in Frugal mode is pretty darn close. Booting from an ISO in Frugal mode that resides on a CD is almost rock solid. Getting root access alone will not allow you to change the CD or ISO.

I haven't used one of the Linux immutable distros. From the description on the page for which the URL was provided, it sounded to me as if there is a typical root file system, but it was made read only. Are you saying that instead those distros. are intended to be run directly off of a CD to DVD?

I am saying if you want a distribution that is truly immutable, we have those. In fact, virtually any distribution that can be run live with persistence can be run that way. It is not the most convenient way, and it requires acquiring a bit more knowledge, but we solved that problem long before we had Linux distributions that CALLED themselves immutable in a way that is more secure and not rendered less secure by providing the user root access.

I was in the process of addressing someone's statement that in this context "root" was not allowed to be root. So it seems we agree.

Well in these cases the user is allowed to become root, and root is allowed full access so it is allowed to be root, but the core of the OS is protected by HARDWARE restrictions. Hardware beats software every time, ask any electrical engineer!

Please give an example of a Linux distro. which is protected by hardware, and the way it is protected by hardware.

See post #3664.
I have used DSL, TinyCore, Puppy Linux, and others this way. It is just the trick for a firewall or other edge device that may suffer attacks from external threat agents (There is nothing they can change that will survive a reboot!).

I saw post #3664 before. I've looked at it again, and I'm sorry if you feel I should be thinking of something you intended, but I'm not. There are various ways to boot from a DVD. Some DVD's are writable. So could you please be more specific.

Sure. Load your OS onto READ ONLY (or write once read many) media and it cannot be changed without replacing the media. Immutable!

When I saw people commenting on immutable distros., I wondered, just in general, if someone starts with a distro. which is not immutable, what type of changes would need to be made to the distro. to allow it to function as an immutable distro? Then I saw comments such as this:

That made it seem to me as if someone thought that if I put the distro. I've used the most, on a DVD, and ran it from the DVD, the distro. would be immutable, even though it was not designed to be immutable. However, just about any distro. which I have used, and which was not intended to be immutable, writes to a variety of directories, and files, devices, that are located on, or accessed through, the root partition.

So just placing a distro. which is not intended to be immutable, on a DVD and running it from the DVD, I can be almost certain that it might not function at all, but at the very least, would have some functionality impaired.

It seems that what I should do is, when I get to the point at which I have the time to satisfy my curiosity in detail, I'll grab an immutable distro. and look through it.

Thanks for the responses.

Coming back (used it at work quite a bit) to Unix/Linux after about 20 years or so, as retiree, I see all these distributions
and related new (for me) things like Haiku, I stumbled upon a discussion in a Haiku forum, where one poster vehemently trashed
Haiku and also Linux.

His main points of attack were (I put Linux and Haiku etc. in the same basket, as he did, and call it just Linux):
1) Windows/Apple 'just works out of the box', i.e all HW is properly detected, no need to hunt all over the net and forums (like this good one)
2) Windows/Apple more stable, 'never crashed'
3) Trust salaried professionals more than 'a bunch of volunteers'.

My own experience:
1) True for the 'just works' part, not sure yet about the frequent need for 'hunting' in Linux, just started with some 'live' sessions.
2) Don't know yet (just starting with Linux again), but XP, Vista, 7, 8,1, 10 indeed never crashed on me, over decades. I still have machines
running all of them just fine.
3) Double-edged. Because Windows and Apple are ultra-commercial I trust them less and less. Their intrusiveness and over-reach is getting
unbearable, see Apple's over-expensive 'eco system' and Window's big brother attitude (starting in full with 8/10/11, 7 is fine)

Resulting question:
What can you, the Linux 'pros', tell someone like me, who starts to hate Windows (never used Apple much), but who also is still a bit
nervous about the attack points listed above, because he on one hand wants an OS that 'just works' for every-day tasks, like Win 7, but on the other
wants to enjoy the freedom (also financially, but less important) and comfortable real 'tech' smell of Linux, as opposed to the big brother and useless gimmicks smell of Windows and the secluded price rip-off of Apple.

Haiku and Linux are exactly in the same basket as Windows and Linux are. Both are operating systems. That's it, basically.

True. Although Windows still does have its quirks (e.g. printers).

Welllllllllllll...
Windows 11 is more stable than Windows 98 was, but you can crash any system, including Haiku, Linux and macOS - some harder, some easier.

Also true.

Are you aware that giant companies make much of their money off Linux?