Xah Lee's Unixism

[Karl A. Krueger]

In comp.lang.lisp Rupert Pigott <roo at try-removing-this.darkboong.demon.co.uk> wrote:
> John Thingstad wrote:
>>
>> As for following standards thats just plain sense.  Note the Mac OS
>> 10 / Darwin uses a unix kernel because of all the problems  with
>> interoperabillity OS 9 had with talking to Windows and Unix boxes.
> 
> Which I believe is derived from a Mach uKernel... The "UNIX" bits
> are the FreeBSD userland utilities that surround it.

Well, no.  Mac OS X uses a BSD kernel implemented on top of the Mach
microkernel, much as Apple's experimental mkLinux placed a Linux kernel
on top of Mach.  OS X also uses a pretty standard set of BSD libraries
and utilities -- as well as the NeXT-derived ones.  (You can tell the
heritage apart pretty easily -- if it's written in Objective-C, it's
from the NeXT side.)

The BSD heritage is a two-way street:  Apple has contributed code
developed for OS X back to the FreeBSD and OpenBSD projects, as well as
releasing the whole Unix core of OS X as the open-source Darwin system.

It's also not particularly accurate to say that the reason Apple moved
to Unix was "interoperability".  Rather, the old Mac System was simply
never designed for what it ended up being used to do.  There were too
many layers of cruft -- and too many design decisions that were right
for 1984 but wrong for 1999.  Single-user, cooperative multitasking, and
a network stack designed for small LANs rather than the Internet ... the
old Mac System was a great microcomputer OS but not a great workstation
OS.

When you consider that the first Macs to run OS X were several hundred
times faster than the 1984 Mac, had one thousand times as much RAM, and
had fifty thousand times as much mass storage, it should follow pretty
naturally that the constraints of the old system's design would cease to
be appropriate.

	1984 Original Macintosh: 128kB RAM, 8MHz m68k, 400kB disk
	1999 Power Macintosh G4: 128MB RAM, 400MHz PPC G4, 20 GB disk

-- 
Karl A. Krueger <kkrueger at example.edu>
Woods Hole Oceanographic Institution
Email address is spamtrapped.  s/example/whoi/
"Outlook not so good." -- Magic 8-Ball Software Reviews