The 92-page report, from a 14-person Washington, D.C., think tank called the Alexis de Tocqueville Institution, suggests more Linux credit should go to Minix. A Unix clone, Minix was designed by Andrew Tanenbaum to help him teach operating systems and software at Vrije University in Amsterdam. Torvalds used Minix before he embarked on Linux development in 1991.
In an e-mail interview, Torvalds strongly disputed the study's conclusions. And Tanenbaum himself has harshly criticised the study.
According to the study, it's safe to argue that Tanenbaum, who had years of OS experience and who had seen the Unix source code, could create Minix in three years. "However, it is highly questionable that Linus, still just a student, with virtually no operating systems development experience, could do the same, especially in one-sixth of the time," says the study, which was written by Ken Brown, president of the Alexis de Tocqueville Institution.
"Why are the most brilliant business minds in the history of PC technology, with hundreds of millions of dollars in capital, licensing Unix source code, if it is as simple as writing it from scratch with little help or experience?" the study asks. "Is it possible that building a Unix operating system really only takes a few months--and, oh by the way, you don't even need the source code to do it?"
Gordon Haff, an engineer and analyst for analysis firm Illuminata, took a more measured view. "I think we can all stipulate that Linux is not a 'clean room' creation. Whether that makes it a derivative work is a question for the lawyers and the philosophers," he said. As for suspicions about Torvalds' rapid early progress, it should be noted "that the original product was quite primitive," he said.
The study comes not long after several attacks on Linux--many of them spurred by Microsoft, whose Windows operating system competes with Linux. More significantly, it arrives in the midst of a legal attack on Linux by the SCO Group, which argues Linux violates its Unix copyrights.
Bolder words
Although the new study raises more questions than it answers, in an interview, Brown was bolder in his claims.
"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," Brown said. "If you sit down with the Ford blueprints and build a Chrysler and don't give Ford any credit, that's not invention."
In an interview conducted for the study, Brown quoted Tanenbaum as saying 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."
If Linux is a derivative work of Minix, that makes Linux vulnerable to charges of intellectual property infringement by Prentice Hall, which published books on Minix, as well as the Minix source code, but restricted its use until 2000, the study said. "Arguably, Prentice Hall has lost out on tens of millions of dollars" because of lost book sales, the study said.
But Torvalds argued that he and other Linux developers have given proper credit.
"Linux never used Minix code...We never credited anybody else's code, because we never used anybody else's code," Torvalds said. But Unix, he said, did provide ideas: "Linux has always credited Unix. There has never been any question about the fact that Linux was very open about taking a lot of good ideas from Unix."
Minix, he said, was simply a platform on top of which Torvalds did his programming work.
The study suggested that Torvalds might have gradually replaced Minix code with Linux, but Torvalds says that did not happen.
"I didn't 'write the Minix code out of Linux,'" Torvalds said. "I was using Minix when I wrote Linux, but that's in the same sense that you are using Windows when you write your columns. Do your articles contain Windows source code because you use Windows to write them?"
Torvalds isn't the only one to dispute the study: Tanenbaum himself sided against Brown.
"Linus didn't sit down in a vacuum and suddenly type in the Linux source code. He had my book, was running Minix and undoubtedly knew the history (since it is in my book). But the code was his," Tanenbaum said in a Web posting about his interview.
"By the time Linus started, five people had independently implemented Unix or something approximating it...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."
Fueling the flames
When the institute announced the pending publication of the report earlier this week--saying it "directly challenges Linus Torvalds' claim to be the inventor of Linux"--it immediately drew criticism from open-source advocates who suggested Linux foe Microsoft was behind the report.
Microsoft indeed has provided funding to the Alexis de Tocqueville Institution for five years, a Microsoft representative said, without disclosing how much has been granted. Microsoft funds several public policy institutes, including the American Enterprise Institute, the Center for Strategic and International Studies, the Heritage Foundation, and the Cato Institute, the representative said.
Brown declined to discuss his organisation's funding sources, but said there are several and that its research is independent. "I publish what I think, and that's it. I don't work for anybody's PR machine," he said.
One area where Brown and Torvalds agree is that Torvalds shouldn't bear the title of Linux "inventor."
"I'd agree that 'inventor' is not necessarily the right word," Torvalds said, to describe his role in Linux.
The study also raises the issue that Torvalds saw Unix source code. This was available in annotated source code that John Lions, a professor at the University of New South Wales in Australia, made available to his classes. The notes were widely distributed illegally afterward, and "many suspect that Linus also had the Lions notes," the report said.
Not true, Torvalds said: "I've never seen the Lions book, although I've obviously heard of it. And no, no Unix source code either."
Brown and his colleagues interviewed more than two dozen people for the study, but Torvalds "didn't get back to us" with requests for comment. Torvalds said he never received any e-mail from the institution.
The Linux issue fuels Brown's concern that open-source software makes it easier for other countries to benefit from U.S. technological prowess, he said: "How are you going to have an intellectual-property economy if you can just rip off stuff?"
Such political and business issues likely will get more attention in a book Brown plans to publish in coming months that will expand on the study.
The study will be sold by an outside e-book seller, Brown said. Although his organisation usually makes studies available on its own, outsiders have crashed the group's Web site twice in recent days, after it published a press release on the upcoming study, Brown said.
The study is at times provocative, but in the end, it isn't revolutionary, Illuminata analyst Haff said: "It doesn't ultimately tell me anything surprising that would cause me to rethink the role of open source".
Tanenbaum responds here:
http://www.cs.vu.nl/~ast/brown/
"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."