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Fifty Years of Operating Systems

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Operating systems are a major enterprise within computing. They are hosted on a billion devices connected to the Internet. They were a $33 billion global market in 2014. The number of distinct new operating systems each decade is growing, from nine introduced in the 1950s to an estimated 350 introduced in the 2010s.a

Operating systems became the subject of productive research in late 1950s. In 1967, the leaders of operating systems research organized the SOSP (symposium on operating systems principles), starting a tradition of biannual SOSP conferences that has continued 50 years. The early identification of operating system principles crystallized support in 1971 for operating systems to become part of the computer science core curriculum (see the sidebar).


R Oldehoeft

How many of those 350 OSs introduced in the 2010s were just variants of (or derivatives from) Linux? That number is excessively inflated.

Linus Torvalds was never Andy Tanenbaum's student (where did that come from?). Andy was at the Vrije Universiteit Amsterdam in the Netherlands, while Linus studied at the University of Helsinki. Linus was frustrated by the education-use-only licensing of Minix, and created Linux starting in 1991. Shortly thereafter, other Unix-like OSs appeared, and Linus has said he probably would not have bothered with Linux if they had been available. Andy seemed to have had quite an antipathy toward Linux and its success, since Minix could never achieve that with its licensing restriction.

Peter Denning

I quoted the Wikipedia numbers because they demonstrate a continued and growing interest in operating systems. I'm sure the details are debatable, but the trend is clear.

That is my mistake saying that Linus Torvalds was Andy Tanenbaum's student. I misinterpreted something Andy said to me. In the March 2016 CACM Andy goes into quite a lot of detail about the relationship between him and Linus as he discusses the 30 year history of MINIX. Nothing he says suggests an antipathy.

Ahmed Almadhoob

I would like to appreciate Mr. Peter J. Denning for that valuable article, and because he admitted and corrected some details. Regarding the number of distinct new operating systems, it is true that the estimated number there does not affect the main idea clearly. To be more clear, academics and professionals should not quote statistics from a collection of user-generated forums (e.g. the Wikipedia). There is a list prepared by the Operating Systems Documentation Project (OSDP). Take a look at the following URL.

Appreciation and acknowledgments.

Peter Denning

I am glad to learn about the OSDP. No one at the SOSP conference mentioned it. I used the crowdsourced Wikipedia data only to make the point that even among "new" operating systems there has been tremendous growth. The growth is likely to continue with the arrival of more "things" in the Internet. Not only is the number systems in the rise, the recent sales figures for revenues to OS vendors ($33 billion) are impressive. OS has become a strong and bustling field.

Chris Hendriks

The author uses the word 'loathed' maybe that he knows Dennis and Ken, but nowhere else, as far as I am aware of, in literature it is stated that strong.

In the summer of '69 Ken produced the first version of Unix in exactly 1 man-month, I understand why the author says '71; it's the year of the first manual ;-) But that is not the Unix spirit, that's why he should write 1969.

Linus Torvalds is mentioned to have been a student of Andy Tanenbaum, if student would have been quoted ("student") it would have been defendable because Linus studied Minix, but Andy wrote once to Linus that if he would have been a student of his he would have given him a low mark for his Linux work (because Linux is a monolithical OS, where the general opinion is that micro kernels are better). So Linus was not a student of Andy.

Peter Denning

Many years ago, one of them said in a speech that the high cost of a Multics system would unfairly keep most programmers away. That was a strong motivation for them to do something much simpler that would fit on the PDP computer in their lab. "Loathed" is strong but reflects my memory of the intensity of their determination to do something better. They succeeded well!

See my previous comment about the relationship between Tanenbaum and Torvalds.

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