* Crossposted in UNIX

Considering the success of the previous :-)

(The follow-up BY TANEBAUM. If you feel he doesn't know what he's talking
about, tell him, not me :-) (http://www.cs.vu.nl/~ast)

>----- Begin -----
Ken Brown's Motivation, Release 1.2

Background

On 20 May 2004, I posted a statement refuting the claim of Ken Brown,
President of the Alexis de Tocqueville Institution, that Linus Torvalds
didn't write Linux. My statement was mentioned on Slashdot, Groklaw, and
many other Internet news sites. This attention resulted in over 150,000
requests to our server in less than a day, which is still standing despite
yesterday being a national holiday with no one there to stand next to it
saying "You can do it. You can do it." Kudos to Sun Microsystems and the
folks who built Apache. My statement was mirrored all over the Internet,
so the number of true hits to it is probably a substantial multiple of
that. There were also quite a few comments at Slashdot, Groklaw, and
other sites, many of them about me. I had never engaged in remote
multishrink psychoanalysis on this scale before, so it was a fascinating
experience.

The Brown Book

I got an advance copy of Ken Brown's book. I think it is still under
embargo, so I won't comment on it. Although I am not an investigative
reporter, even I know it is unethical to discuss publications
still under embargo. Some of us take ethics more seriously than
others. So I won't even reveal the title. Let's call it The Brown
Book. There is some precedent for nicknaming books after colors:
The International Standard for the audio CD (IS 10149) is usually
called The Red Book. The CD-ROM was described in the Yellow Book.

Suffice it to say, there is a great deal to criticize in the book. I
am sure that will happen when it is published. I may even help out.

Brown's Motivation

What prompted me to write this note today is an email I got yesterday.
Actually, I got quite a few :-) , most of them thanking me for the
historical material. One of yesterday's emails was from Linus, in
response to an email from me apologizing for not letting him see my
statement in advance. As a matter of courtesy, I did try but I was
using his old transmeta.com address and didn't know his new one until
I got a very kind email from Linus' father, a Finnish journalist.

In his email, Linus said that Brown never contacted him. No email,
no phone call, no personal interview. Nothing. Considering the fact
that Brown was writing an explosive book in which he accused Linus
of not being the author of Linux, you would think a serious author
would at least confront the subject with the accusation and give him
a chance to respond. What kind of a reporter talks to people on the
periphery of the subject but fails to talk to the main player?

Why did Brown fly all the way to Europe to interview me and (and
according to an email I got from his seat-mate on the plane) one other
person in Scandinavia, at considerable expense, and not at least
call Linus? Even if he made a really bad choice of phone company,
how much could that cost? Maybe a dollar? I call the U.S. all the
time from Amsterdam. It is less than 5 cents a minute. How much
could it cost to call California from D.C.?

From reading all the comments posted yesterday, I am now beginning
to get the picture. Apparently a lot of people (still) think that
I 'hate' Linus for stealing all my glory (see below for more on
this). I didn't realize this view was so widespread. I now suspect
that Brown believed this, too, and thought that I would be happy
to dump all over Linus to get 'revenge.' By flying to Amsterdam he
thought he could dig up dirt on Linus and get me to speak evil of
him. He thought I would back up his crazy claim that Linus stole
Linux from me. Brown was wrong on two counts. First, I bear no
'grudge' against Linus at all. He wrote Linux himself and deserves
the credit. Second, I am really not a mean person.  Even if I were
still angry with him after all these years, I wouldn't choose some
sleazy author with a hidden agenda as my vehicle. My home page gets
2500 hits a week. If I had something to say, I could put it there.

When The Brown Book comes out, there will no doubt be a lot of
publicity in the mainstream media. Any of you with contacts in
the media are actively encouraged to point reporters to this page
and my original statement to provide some balance. I really think
Brown's motivation should come under scrutiny. I don't believe for
a nanosecond that Brown was trying to do a legitimate study of IP
and open source or anything like that. I think he was trying to
make the case the people funding him (which he refused to disclose
to me despite my asking point blank) wanted to have made. Having an
institution with an illustrious-sounding name make the case looks
better than having an interested party make the case.

   Clearing Up Some Misconceptions

I would like to close by clearing up a few misconceptions and also
correcting a couple of errors. First, I REALLY am not angry with
Linus.  HONEST. He's not angry with me either. I am not some kind of
"sore loser" who feels he has been eclipsed by Linus. MINIX was only
a kind of fun hobby for me. I am a professor. I teach and do research
and write books and go to conferences and do things professors do. I
like my job and my students and my university. If you want to get
a masters there, see my home page for information. I wrote MINIX
because I wanted my students to have hands-on experience playing
with an operating system.  After AT&T forbade teaching from John
Lions book, I decided to write a UNIX-like system for my students
to play with. Since I had already written two books at this point,
one on computer architecture and one on computer networks, it seemed
reasonable to describe the system in a new book on operating systems,
which is what I did. I was not trying to replace GNU/HURD or Berkeley
UNIX. Heaven knows, I have said this enough times. I just wanted to
show my students and other students how you could write a UNIX-like
system using modern technology. A lot of other people wanted a free
production UNIX with lots of bells and whistles and wanted to convert
MINIX into that. I was dragged along in the maelstrom for a while,
but when Linux came along, I was actually relieved that I could go
back to professoring. I never really applied for the position of
King of the Hackers and didn't want the job when it was offered.
Linus seems to be doing excellent work and I wish him much success
in the future.

While writing MINIX was fun, I don't really regard it as the most
important thing I have ever done. It was more of a distraction than
anything else. The most important thing I have done is produce a
number of incredibly good students, especially Ph.D. students. See
my home page for the list. They have done great things. I am as
proud as a mother hen. To the extent that Linus can be counted as
my student, I'm proud of him, too. Professors like it when their
students go on to greater glory.  I have also written over 100
published research papers and 14 books which have been translated
into about 20 languages. As a result I have become a Fellow of the
IEEE, a Fellow of the ACM, and won numerous other awards. For me,
these are the things that really count. If MINIX had become a big
'commercial' success I wouldn't have had the time to do all this
academic stuff that I am actually more interested in.

   Microkernels Revisited

I can't resist saying a few words about microkernels. A microkernel
is a very small kernel. If the file system runs inside the kernel,
it is NOT a microkernel. The microkernel should handle low-level
process management, scheduling, interprocess communication,
interrupt handling, and the basics of memory management and little
else. The core microkernel of MINIX 1.0 was under 1400 lines of
C and assembler. To that you have to add the headers and device
drivers, but the totality of everything that ran in kernel mode
was under 5000 lines. Microsoft claimed that Windows NT 3.51 was
a microkernel. It wasn't. It wasn't even close. Even they dropped
the claim with NT 4.0. Some microkernels have been quite successful,
such as QNX and L4. I can't for the life of me see why people object
to the 20% performance hit a microkernel might give you when they
program in languages like Java and Perl where you often get a factor
20x performance hit. What's the big deal about turning a 3.0 GHz
PC into a 2.4 GHz PC due to a microkernel? Surely you once bought
a machine appreciably slower than 2.4 GHz and were very happy with
it. I would easily give up 20% in performance for a system that was
robust, reliable, and wasn't susceptible to many of the ills we see
in today's massive operating systems.

   Correction

I would now like to correct an error in my original statement. One
of the emails I got yesterday clarified the origins of Coherent. It
was not written by Bob Swartz. He was CEO of the Mark Williams
Company. Three ex-students from the University of Waterloo,
Dave Conroy, Randall Howard, and Johann George, did most of the
work. Waterloo is in Canada, where they also play baseball I am told,
but only after the ice melts and they can't play hockey. It took the
Waterloo students something like 6 man-years to produce Coherent,
but this included the kernel, the C compiler, the shell, and ALL
the utilities. The kernel is only a tiny fraction of the total code,
so it may well be that the kernel itself took a man year. It took me
three years to write MINIX, but I was only working at it only in the
evenings, and I also wrote 400 pages of text describing the code in
that time period (also in the evenings). I think a good programmer
can write a 12,000 line kernel in a year.

If you have made it this far, thank you for your time. Permission is
hereby granted to mirror this web page provided that the original,
unmodified version is used.

Andy Tanenbaum, 21 May 2004

>-----  End  -----

Francois

--- FMailX 1.48b