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'Not the sharpest of knives' - praise heaped on Linux study author

Tanenbaum speaks

Previous suggestions that the Alexis de Tocqueville Institution would be publishing excerpts from its damning indictment of Linus Torvalds today would appear to be inoperative. According to the AdTI front page free copies are available for "Tocqueville supporters only", the study will be available for purchase from around 20:00 GMT today, and free review copies can be obtained by working press and academics "(copyright agreement required)".*

That last bit will have an obvious effect on a pretty large number of people who might be expected to take some issue with the opus, but considering how slick the rest of the AdTI marketing operation has been, we feel sure this was entirely unintentional. The AdTI first published a press release implying great things from a forthcoming work from Institution president Kenneth Brown. It was however couched in sufficiently weasel terms for one to deduce that the final work would not actually claim flat-out that Linus Torvalds is a liar. Subsequent claims along the lines of there being "a high probability that Linux is a derivative work" (Gregory Fossedal of AdTI to Newsfactor) seem to support this view.

The release trailed a study by Brown challenging Torvalds "claim to be the inventor of Linux", said that it was part of a forthcoming book on open source software, and that excerpts from the book would be published at today. Shortly after the publication of the release, the AdTI site fell over. Brown tells CNET that 'outsiders' have crashed his web site twice in recent days, however The Register's observations of said crashed site led us to believe that it was merely the site of an outfit which had not bought enough bandwidth to cope with the amount of publicity it had actively solicited. But Brown's right - there really is a shocking number of outsiders on the internet these days, and there should be a law against it.

Whatever. The site stayed up long enough to pick of a goodly amount of free publicity (including from us, but we tend to view 'all publicity is good publicity' as a challenge we should endeavour to meet), and is therefore able to bring us its "advance review" notices today. We presume the site will fall over again in a minute, so for your convenience, these are as follows: ZDNET/CNET, twice, and young Shankland shows every sign of having possession of the report; LinuxInsider, which seems not to have the report, but does have soundbites from Brown claiming he's in favour of open source and accusing Torvalds of having a "smarmy attitude"; NewsFactor, no report, soundbites from Brown and Fossedal, and Techno Babble, whose "advance review" is actually the original press release.

Young Shankland seeming to have done us all the service of reading it so we don't have to, he should be our next stop. The report seems to point at Minix, written by Andrew Tanenbaum, as being the real origin of Linux, but Shankland indicates that verbally Brown is "bolder in his claims", saying: "It's clear to me, at least from quotes from Tanenbaum, that Linus started from Minix... He just sat down with Minix and wrote this product. By definition, that is not an invention. If you sit down with the Ford blueprints and build a Chrysler and don't give Ford any credit, that's not invention." The report itself seems to cast doubt on the ability of a student to write a full-blown OS in three months.

The actual Tanenbaum quote, for which we should again thank Shankland, is that Minix "was the base that Linus used to create Linux. He also took many ideas from Minix, including the file system, source tree and much more." This would appear to be the foundation on which Brown's entire edifice is constructed.

Over now to Tanenbaum himself, who has made an entertaining attempt to set the record straight here (you may not get in right now, as traffic is already heavy). He observes that Brown, who flew to Amsterdam to interview him in March, is "not the sharpest knife in the drawer", and says: " I quickly determined that he didn't know a thing about the history of UNIX, had never heard of the Salus book, and knew nothing about BSD and the AT&T lawsuit. I started to tell him the history, but he stopped me and said he was more interested in the legal aspects. I said: 'Oh you mean about Dennis Ritchie's patent number 4135240 on the setuid bit?' Then I added: 'That's not a problem. Bell Labs dedicated the patent.' That's when I discovered that (1) he had never heard of the patent, (2) did not know what it meant to dedicate a patent (i.e., put it in the public domain), and (3) really did not know a thing about intellectual property law. He was confused about patents, copyrights, and trademarks. Gratuitously, I asked if he was a lawyer, but it was obvious he was not and he admitted it. At this point I was still thinking he might be a spy from SCO, but if he was, SCO was not getting its money's worth."

So far so good? Brown pressed on doggedly: "He wanted to go on about the ownership issue, but he was also trying to avoid telling me what his real purpose was, so he didn't phrase his questions very well. Finally he asked me if I thought Linus wrote Linux. I said that to the best of my knowledge, Linus wrote the whole kernel himself, but after it was released, other people began improving the kernel, which was very primitive initially, and adding new software to the system -- essentially the same development model as MINIX. Then he began to focus on this, with questions like: 'Didn't he steal pieces of MINIX without permission.' I told him that MINIX had clearly had a huge influence on Linux in many ways, from the layout of the file system to the names in the source tree, but I didn't think Linus had used any of my code. Linus also used MINIX as his development platform initially, but there was nothing wrong with that. He asked if I objected to that and I said no, I didn't, people were free to use it as they wished for noncommercial purposes. Later MINIX was released under the Berkeley license, which freed it up for all purposes. It is still in surprisingly wide use, both for education and in the Third World, where millions of people are happy as a clam to have an old castoff 1-MB 386, on which MINIX runs just fine. The MINIX home page cited above still gets more than 1000 hits a week.

"Finally, Brown began to focus sharply. He kept asking, in different forms, how one person could write an operating system all by himself. He simply didn't believe that was possible. So I had to give him more history, sigh. To start with, Ken Thompson wrote UNICS for the PDP-7 all by himself. When it was later moved to the PDP-11 and rewritten in C, Dennis Ritchie joined the team, but primarily focused on designing the C language, writing the C compiler, and writing the I/O system and device drivers. Ken wrote nearly all of the kernel himself...

"By the time Linus started, five people had independently implemented the UNIX kernel or something approximating it, namely, Thompson, Swartz, Holt, Comer, and me. All of this was perfectly legal and nobody stole anything. Given this history, it is pretty hard to make a case that one person can't implement a system of the complexity of Linux, whose original size was about the same as V1.0 of MINIX."

It would appear therefore that Brown went into the interview with Tanenbaum with the view that Torvalds must have stolen Linux and couldn't possibly have written it, that Tanenbaum went to great pains to disabuse him of this entirely unfounded notion, and that Brown emerged sufficiently unsullied by knowledge to just carry on and write his "path-breaking study".

Says Tanenbaum: "My conclusion is [that] Ken Brown doesn't have a clue what he is talking about. I also have grave questions about his methodology. After he talked to me, he prowled the university halls buttonholing random students and asking them questions. Not exactly primary sources.

"The six people I know of who (re)wrote UNIX all did it independently and nobody stole anything from anyone. Brown's remark that people have tried and failed for 30 years to build UNIX-like systems is patent nonsense. Six different people did it independently of one another. In science it is considered important to credit people for their ideas, and I think Linus has done this far less than he should have. Ken and Dennis are the real heros here. But Linus sloppiness about attribution is no reason to assert that Linus didn't write Linux. He didn't write CTSS and he didn't write MULTICS and didn't write UNIX and he didn't write MINIX, but he did write Linux. I think Brown owes a number of us an apology."

That all cleared up then? Nothing more to see here folks, move along... ®

* And then it says "click here". Naturally, we didn't, but an intrepid soul who did tells us it then lets you send an email to "" (sic). It's possible you might then have to wait a while. Thanks to intrepid soul Dave Korn for the tip.

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