John Hinsley wrote:

> But surely there's a history to this..... I just wonder why, 
> given that Unix preceded DOS and Mac, they both decided to
> do things differently?

[Pardon the hidden soapbox - This is all IMHO]

You're assuming they came from the same OS design traditions.
They don't really.... Unix seems to be old enough that it
can be considered something that started "fresh" while
DOS has it's roots in CP/M which was (if I followed the 
trail of breadcrumbs correctly) essentially a "clone" of 
one of Digital Equipment Corp.'s PDP-11 operating systems 
(RSX-11 ?).

So Unix comes from a "research" orientation while
DOS can be traced back to a "business" orientation
and it shows... the goal (though it seems to have lost
focus since then) was "safety" and "comfort" for the
PHB's. (What matters is the "data" not the OS it
sits on)

As far as the Mac goes ? No real idea other than
it was possibly Apple's interpretation of the work 
going on at Xerox PARC filtered through the lens 
of the Apple II.....

And that bias still exists....


> (But I'd imagine that the Smalltalk 80 people were all developing on
> Macs, so that the choice sort of followed on from that....) I wonder
> which tradition OS X follows?

Most likely some combination of Mac & Unix (due to its' Unix roots)

I try to avoid OS religious wars myself.... mostly because
I have to deal with most of them at some point or other
for work purposes and can't really afford to get involved
in such things. 

My preference (if I had/have a voice at some point in this) would
be something flexible enough that new OS's can be added to the
Squeak "fold" without worrying about such things as line separators.
But other than following this discussion I haven't thought a lot
about it yet beyond that...

-Andy-