> "Operating system" is a very clear expression that means exactly one thing.
That's not correct at all. An "Operating System" can mean many things and there's tremendous debate in the OS and Systems community over the definition.
That's not correct at all. An "Operating System" can mean many things and there's tremendous debate in the OS and Systems community over the definition.
There are a lot of debates about whether X or Y should be a function of the operating system, but that doesn't justify OP's position. Applications that come with the operating system are not part of the operating system, you know, on account of them being separate applications. Unless I missed the debate on whether grep and emacs are essential parts of Linux or not.
The questions you quote are much like the heap paradox, but that doesn't make the concept of operating system so flexible that you can bend it to mean anything. Also, let's be honest here -- quite a few of those questions are there only because at some point in history, fanboys of one platform wanted to rest their fanboyism on some sort of technical grounds, which is how we ended up with fundamentalist-like questions of the "should the OS provide a GUI" sort.
Here's GNU's definition of a Unix-like, "A Unix-like operating system is a software collection of applications, libraries, and developer tools, plus a program to allocate resources and talk to the hardware, known as a kernel." This is a very heavy idea of an OS and grep and emacs sound like "developer tools" and "applications". Most OS people involved in unix-like OSs would be aghast if you didn't at least include some basic userspace applications like cat and ls.
GNU isn't specific about what needs to be in the collection of things to constitute a unix-like OS, but it looks like that agrees in most respects to bookwormAT, "'operating system' is a very generic expression. For most people today an operating system is the software that is installed on the device minus applications that the user installed himself."
GNU's concept is miles different from very light concepts of an embedded OS's like Femto OS which near as I can tell is pretty much just a kernel and some libraries.
WP on the other hand says, "An operating system (OS) is a collection of software that manages computer hardware resources and provides common services for computer programs." So strictly speaking, by this definition an OS doesn't even need to provide disk access like the old DOSs!
Although of course it later contradicts itself and says "Access to data stored on disks is a central feature of all operating systems." which anybody involved in the OS community knows is not a central feature of "all" operating systems. I've used OSs where useful file system access was provided via userspace applications (a la FUSE).
Palantir takes the position that an OS doesn't need to be interacting or managing the hardware stuff, just providing the ability to run different hosted applications is enough, making things like web browsers operating systems (http://www.palantir.com/2009/11/palantir-like-an-operating-s...)
bookwormATs position is that not only are OSs heavy things, but that "Android" is not just an OS, but a meta-OS description of what an Android OS should be (just like XML is a meta-language for describing XML compatible file formats).
So if GNU's definition is correct (and lots of people subscribe to GNU's position), bookwormATs position, "'operating system' is a very generic expression. For most people today an operating system is the software that is installed on the device minus applications that the user installed himself." is correct.
Is it an OS's job to...
-provide a Graphical Interface?
-provide any interface?
-handle a hardware abstraction layer?
-handle font rendering?
-composite graphical displays?
-provide an abstract virtual machine environment across different processor types?
-handle user accounts? What about systems that aren't multi-user?
-does an OS need to handle virtual memory to be an OS? what if all memory management (virtual or otherwise) is handled by a dedicated support chip instead?
Some more:
-does the simple timing code on a $1 digital watch count as an OS?
-does a system that, when turned on, goes automatically to a memory address for more instructions, and those instructions are only the instructions for a user program count as having an OS (lots and lots of computers past and present are like this)?
-does an OS provide software beyond just the Kernel? e.g. Start with a modern linux distro and start removing packages, at what point is it no longer an OS? (GNU would like you to think it's an OS only when you have GNU userspace tools, X etc. on it. )
-is an OS just a space to host and run programs? Does that make the JVM an OS? How about a browser? How about MS-Excel and Macros?
-the OS I'm using right now ships with a paint program, a calculator a browser and a text editor, must an OS have those things?
-how about a system with a complex BIOS that happens to have USB, Ethernet support and a web browser? Is the boot code now an OS? When does bootcode become an OS if this isn't it?
-should an OS handle all available hardware on a system or just some subset?
-what is the first OS in history?
etc. etc. etc.
At some point, somewhere between boot loader and a fully loaded gaming system there exists this thing called an OS. It seems to be more than just a kernel, unless it's an embedded system with basically just a kernel (unless the system is so small and dedicated it just runs code directly without an OS layer (unless you count the code that's running and doing its own resource management an OS since by definition an OS does resource management)), or it seems to be resource management code that also happens to have nice font rendering and a full networking stack. The debate goes much deeper and has gone on for decades.