🚀 go-pugleaf

In comp.unix.questions Jeffrey Siegal <jbs@quiotix.com> wrote:
: Isaac wrote:
:> The definition I recall from CSC-501 was that that an operating system
:> was the software layered over top of the computer hardware that provided
:> services making it easier to write programs.  Things typically provided
:> by such a system are IO services, support for, multi-tasking and process
:> scheduling, management of storage devices, control of peripherals
:> among other things.
:> 
:> I would consider that to be at least one conventional definition.  It's the
:> one that was in most OS textbooks in the early nineties.  The linux kernel
:> certainly fits that definition.   But of course so might software layered
:> over or used in conjunction with the kernel if people actually write
:> their programs to that layer rather than to the kernel.

: So you're suggesting that if X is an operating system, then some part of
: X, call it Y, is also itself an "operating system" if it "provides
: services making it easier to write programs?"  

: That seems absurd for the simple reason that when people usually refer
: to *the* operating system (signular) running on a computer being a
: complete entity with components having other names (device drivers,
: memory manager, authentication, kernel, possibly GUI, and so forth).  I
: don't think I've ever seen an operating system referred to as a
: collection of components each of which is also consider to be an
: operating system (odd cases such as virtual machine managers excluded).

Trying to find the dividing line between OS and not OS is impossible.
Consider: Is a device driver part of the OS only when it is compiled
into the kernel?  If you move it out to a module is it still part
of the OS?  What about if it is a seperate process altogether and not
part of the kernel at all?  As time goes on, stuff that was once
considered a userland problem to deal with often gets moved into
the OS itself.  And since a well designed OS is going to have many
layers that can be peeled away, the dividing line really is fuzzy.
Deal with it.  (I'm glad the DOJ didn't pursue the "split MS into
OS and application companies" solution to their evil practices.
While I agree that MS got where it is through evil unethical means,
I was scared of the prospect of the government deciding where the
dividing line between OS and App is when even technical people don't
have a hard and fast definition.  It's like trying to define what
does and doesn't count as a "high level" programming language.)