GNU'S NOT UNIX

Conducted by David Betz and Jon Edwards

Richard Stallman discusses his public-domain

UNIX-compatible software system

with BYTE editors

(July 1986)

Copyright (C) 1986 Richard Stallman. Permission is granted to make and distribute copies of this article as long as the copyright and this notice appear on all copies.

Richard Stallman has undertaken probably the most ambitious free software development project to date, the GNU system. In his GNU Manifesto, published in the March 1985 issue of Dr. Dobb's Journal, Stallman described GNU as a "complete Unix-compatible software system which I am writing so that I can give it away free to everyone who can use it... Once GNU is written, everyone will be able to obtain good system software free, just like air." (GNU is an acronym for GNU's Not UNIX; the "G" is pronounced.)

Stallman is widely known as the author of EMACS, a powerful text editor that he developed at the MIT Artificial Intelligence Laboratory. It is no coincidence that the first piece of software produced as part of the GNU project was a new implementation of EMACS. GNU EMACS has already achieved a reputation as one of the best implementations of EMACS currently available at any price.

BYTE: We read your GNU Manifesto in the March 1985 issue of Dr. Dobb's. What has happened since? Was that really the beginning, and how have you progressed since then?

Stallman: The publication in Dr. Dobb's wasn't the beginning of the project. I wrote the GNU Manifesto when I was getting ready to start the project, as a proposal to ask computer manufacturers for funding. They didn't want to get involved, and I decided that rather than spend my time trying to pursue funds, I ought to spend it writing code. The manifesto was published about a year and a half after I had written it, when I had barely begun distributing the GNU EMACS. Since that time, in addition to making GNU EMACS more complete and making it run on many more computers, I have nearly finished the optimizing C compiler and all the other software that is needed for running C programs. This includes a source-level debugger that has many features that the other source-level debuggers on UNIX don't have. For example, it has convenience variables within the debugger so you can save values, and it also has a history of all the values that you have printed out, making it tremendously easier to chase around list structures.

BYTE: You have finished an editor that is now widely distributed and you are about to finish the compiler.

Stallman: I expect that it will be finished this October. BYTE: What about the kernel?

Stallman: I'm currently planning to start with the kernel that was written at MIT and was released to the public recently with the idea that I would use it. This kernel is called TRIX; it's based on remote procedure call. I still need to add compatibility for a lot of the features of UNIX which it doesn't have currently. I haven't started to work on that yet. I'm finishing the compiler before I go to work on the kernel. I am also going to have to rewrite the file system. I intend to make it failsafe just by having it write blocks in the proper order so that the disk structure is always consistent. Then I want to add version numbers. I have a complicated scheme to reconcile version numbers with the way people usually use UNIX. You have to be able to specify filenames without version numbers, but you also have to be able to specify them with explicit version numbers, and these both need to work with ordinary UNIX programs that have not been modified in any way to deal with the existence of this feature. I think I have a scheme for doing this, and only trying it will show me whether it really does the job.

BYTE: Do you have a brief description you can give us as to how GNU as a system will be superior to other systems? We know that one of your goals is to produce something that is compatible with UNIX. But at least in the area of file systems you have already said that you are going to go beyond UNIX and produce something that is better.

Stallman: The C compiler will produce better code and run faster. The debugger is better. With each piece I may or may not find a way to improve it. But there is no one answer to this question. To some extent I am getting the benefit of reimplementation, which makes many systems much better. To some extent it's because I have been in the field a long time and worked on many other systems. I therefore have many ideas to bring to bear. One way in which it will be better is that practically everything in the system will work on files of any size, on lines of any size, with any characters appearing in them. The UNIX system is very bad in that regard. It's not anything new as a principle of software engineering that you shouldn't have arbitrary limits. But it just was the standard practice in writing UNIX to put those in all the time, possibly just because they were writing it for a very small computer. The only limit in the GNU system is when your program runs out of memory because it tried to work on too much data and there is no place to keep it all.

BYTE: And that isn't likely to be hit if you've got virtual memory. You may just take forever to come up with the solution.

Stallman: Actually these limits tend to hit in a time long before you take forever to come up with the solution.

BYTE: Can you say something about what types of machines and environments GNU EMACS in particular has been made to run under? It's now running on VAXes; has it migrated in any form to personal computers?

Stallman: I'm not sure what you mean by personal computers. For example, is a Sun a personal computer? GNU EMACS requires at least a megabyte of available memory and preferably more. It is normally used on machines that have virtual memory. Except for various technical problems in a few C compilers, almost any machine with virtual memory and running a fairly recent version of UNIX will run GNU EMACS, and most of them currently do.

BYTE: Has anyone tried to port it to Ataris or Macintoshes? Stallman: The Atari 1040ST still doesn't have quite enough memory. The next Atari machine, I expect, will run it. I also think that future Ataris will have some forms of memory mapping. Of course, I am not designing the software to run on the kinds of computers that are prevalent today. I knew when I started this project it was going to take a few years. I therefore decided that I didn't want to make a worse system by taking on the additional challenge of making it run in the currently constrained environment. So instead I decided I'm going to write it in the way that seems the most natural and best. I am confident that in a couple of years machines of sufficient size will be prevalent. In fact, increases in memory size are happening so fast it surprises me how slow most of the people are to put in virtual memory; I think it is totally essential.

BYTE: I think people don't really view it as being necessary for single-user machines.

Stallman: They don't understand that single user doesn't mean single program. Certainly for any UNIX-like system it's important to be able to run lots of different processes at the same time even if there is only one of you. You could run GNU EMACS on a nonvirtual-memory machine with enough memory, but you couldn't run the rest of the GNU system very well or a UNIX system very well.

BYTE: How much of LISP is present in GNU EMACS? It occurred to me that it may be useful to use that as a tool for learning LISP.

Stallman: You can certainly do that. GNU EMACS contains a complete, although not very powerful, LISP system. It's powerful enough for writing editor commands. It's not comparable with, say, a Common LISP System, something you could really use for system programming, but it has all the things that LISP needs to have.

BYTE: Do you have any predictions about when you would be likely to distribute a workable environment in which, if we put it on our machines or workstations, we could actually get reasonable work done without using anything other than code that you distribute?

Stallman: It's really hard to say. That could happen in a year, but of course it could take longer. It could also conceivably take less, but that's not too likely anymore. I think I'll have the compiler finished in a month or two. The only other large piece of work I really have to do is in the kernel. I first predicted GNU would take something like two years, but it has now been two and a half years and I'm still not finished. Part of the reason for the delay is that I spent a lot of time working on one compiler that turned out to be a dead end. I had to rewrite it completely. Another reason is that I spent so much time on GNU EMACS. I originally thought I wouldn't have to do that at all.

BYTE: Tell us about your distribution scheme. Stallman: I don't put software or manuals in the public domain, and the reason is that I want to make sure that all the users get the freedom to share. I don't want anyone making an improved version of a program I wrote and distributing it as proprietary. I don't want that to ever be able to happen. I want to encourage the free improvements to these programs, and the best way to do that is to take away any temptation for a person to make improvements nonfree. Yes, a few of them will refrain from making improvements, but a lot of others will make the same improvements and they'll make them free.

BYTE: And how do you go about guaranteeing that? Stallman: I do this by copyrighting the programs and putting on a notice giving people explicit permission to copy the programs and change them but only on the condition that they distribute under the same terms that I used, if at all. You don't have to distribute the changes you make to any of my programs--you can just do it for yourself, and you don't have to give it to anyone or tell anyone. But if you do give it to someone else, you have to do it under the same terms that I use.

BYTE: Do you obtain any rights over the executable code derived from the C compiler?

Stallman: The copyright law doesn't give me copyright on output from the compiler, so it doesn't give me a way to say anything about that, and in fact I don't try to. I don't sympathize with people developing proprietary products with any compiler, but it doesn't seem especially useful to try to stop them from developing them with this compiler, so I am not going to.

BYTE: Do your restrictions apply if people take pieces of your code to produce other things as well?

Stallman: Yes, if they incorporate with changes any sizable piece. If it were two lines of code, that's nothing; copyright doesn't apply to that. Essentially, I have chosen these conditions so that first there is a copyright, which is what all the software hoarders use to stop everybody from doing anything, and then I add a notice giving up part of those rights. So the conditions talk only about the things that copyright applies to. I don't believe that the reason you should obey these conditions is because of the law. The reason you should obey is because an upright person when he distributes software encourages other people to share it further.

BYTE: In a sense you are enticing people into this mode of thinking by providing all of these interesting tools that they can use but only if they buy into your philosophy.

Stallman: Yes. You could also see it as using the legal system that software hoarders have set up against them. I'm using it to protect the public from them.

BYTE: Given that manufacturers haven't wanted to fund the project, who do you think will use the GNU system when it is done?

Stallman: I have no idea, but it is not an important question. My purpose is to make it possible for people to reject the chains that come with proprietary software. I know that there are people who want to do that. Now, there may be others who don't care, but they are not my concern. I feel a bit sad for them and for the people that they influence. Right now a person who perceives the unpleasantness of the terms of proprietary software feels that he is stuck and has no alternative except not to use a computer. Well, I am going to give him a comfortable alternative. Other people may use the GNU system simply because it is technically superior. For example, my C compiler is producing about as good a code as I have seen from any C compiler. And GNU EMACS is generally regarded as being far superior to the commercial competition. And GNU EMACS was not funded by anyone either, but everyone is using it. I therefore think that many people will use the rest of the GNU system because of its technical advantages. But I would be doing a GNU system even if I didn't know how to make it technically better because I want it to be socially better. The GNU project is really a social project. It uses technical means to make a change in society.

BYTE: Then it is fairly important to you that people adopt GNU. It is not just an academic exercise to produce this software to give it away to people. You hope it will change the way the software industry operates.

Stallman: Yes. Some people say no one will ever use it because it doesn't have some attractive corporate logo on it, and other people say that they think it is tremendously important and everyone's going to want to use it. I have no way of knowing what is really going to happen. I don't know any other way to try to change the ugliness of the field that I find myself in, so this is what I have to do.

BYTE: Can you address the implications? You obviously feel that this is an important political and social statement.

Stallman: It is a change. I'm trying to change the way people approach knowledge and information in general. I think that to try to own knowledge, to try to control whether people are allowed to use it, or to try to stop other people from sharing it, is sabotage. It is an activity that benefits the person that does it at the cost of impoverishing all of society. One person gains one dollar by destroying two dollars' worth of wealth. I think a person with a conscience wouldn't do that sort of thing except perhaps if he would otherwise die. And of course the people who do this are fairly rich; I can only conclude that they are unscrupulous. I would like to see people get rewards for writing free software and for encouraging other people to use it. I don't want to see people get rewards for writing proprietary software because that is not really a contribution to society. The principle of capitalism is the idea that people manage to make money by producing things and thereby are encouraged to do what is useful, automatically, so to speak. But that doesn't work when it comes to owning knowledge. They are encouraged to do not really what's useful, and what really is useful is not encouraged. I think it is important to say that information is different from material objects like cars and loaves of bread because people can copy it and share it on their own and, if nobody attempts to stop them, they can change it and make it better for themselves. That is a useful thing for people to do. This isn't true of loaves of bread. If you have one loaf of bread and you want another, you can't just put your loaf of bread into a bread copier. you can't make another one except by going through all the steps that were used to make the first one. It therefore is irrelevant whether people are permitted to copy it--it's impossible. Books were printed only on printing presses until recently. It was possible to make a copy yourself by hand, but it wasn't practical because it took so much more work than using a printing press. And it produced something so much less attractive that, for all intents and purposes, you could act as if it were impossible to make books except by mass producing them. And therefore copyright didn't really take any freedom away from the reading public. There wasn't anything that a book purchaser could do that was forbidden by copyright. But this isn't true for computer programs. It's also not true for tape cassettes. It's partly false now for books, but it is still true that for most books it is more expensive and certainly a lot more work to Xerox them than to buy a copy, and the result is still less attractive. Right now we are in a period where the situation that made copyright harmless and acceptable is changing to a situation where copyright will become destructive and intolerable. So the people who are slandered as "pirates" are in fact the people who are trying to do something useful that they have been forbidden to do. The copyright laws are entirely designed to help people take complete control over the use of some information for their own good. But they aren't designed to help people who want to make sure that the information is accessible to the public and stop others from depriving the public. I think that the law should recognize a class of works that are owned by the public, which is different from public domain in the same sense that a public park is different from something found in a garbage can. It's not there for anybody to take away, it's there for everyone to use but for no one to impede. Anybody in the public who finds himself being deprived of the derivative work of something owned by the public should be able to sue about it.

BYTE: But aren't pirates interested in getting copies of programs because they want to use those programs, not because they want to use that knowledge to produce something better?

Stallman: I don't see that that's the important distinction. More people using a program means that the program contributes more to society. You have a loaf of bread that could be eaten either once or a million times.

BYTE: Some users buy commercial software to obtain support. How does your distribution scheme provide support?

Stallman: I suspect that those users are misled and are not thinking clearly. It is certainly useful to have support, but when they start thinking about how that has something to do with selling software or with the software being proprietary, at that point they are confusing themselves. There is no guarantee that proprietary software will receive good support. Simply because sellers say that they provide support, that doesn't mean it will be any good. And they may go out of business. In fact, people think that GNU EMACS has better support than commercial EMACSes. One of the reasons is that I'm probably a better hacker than the people who wrote the other EMACSes, but the other reason is that everyone has sources and there are so many people interested in figuring out how to do things with it that you don't have to get your support from me. Even just the free support that consists of my fixing bugs people report to me and incorporating that in the next release has given people a good level of support. You can always hire somebody to solve a problem for you, and when the software is free you have a competitive market for the support. You can hire anybody. I distribute a service list with EMACS, a list of people's names and phone numbers and what they charge to provide support.

BYTE: Do you collect their bug fixes? Stallman: Well, they send them to me. I asked all the people who wanted to be listed to promise that they would never ask any of their customers to keep secret whatever they were told or any changes they were given to the GNU software as part of that support.

BYTE: So you can't have people competing to provide support based on their knowing the solution to some problem that somebody else doesn't know.

Stallman: No. They can compete based on their being clever and more likely to find the solution to your problem, or their already understanding more of the common problems, or knowing better how to explain to you what you should do. These are all ways they can compete. They can try to do better, but they cannot actively impede their competitors.

BYTE: I suppose it's like buying a car. You're not forced to go back to the original manufacturer for support or continued maintenance.

Stallman: Or buying a house--what would it be like if the only person who could ever fix problems with your house was the contractor who built it originally? That is the kind of imposition that's involved in proprietary software. People tell me about a problem that happens in UNIX. Because manufacturers sell improved versions of UNIX, they tend to collect fixes and not give them out except in binaries. The result is that the bugs don't really get fixed.

BYTE: They're all duplicating effort trying to solve bugs independently. Stallman: Yes. Here is another point that helps put the problem of proprietary information in a social perspective. Think about the liability insurance crisis. In order to get any compensation from society, an injured person has to hire a lawyer and split the money with that lawyer. This is a stupid and inefficient way of helping out people who are victims of accidents. And consider all the time that people put into hustling to take business away from their competition. Think of the pens that are packaged in large cardboard packages that cost more than the pen--just to make sure that the pen isn't stolen. Wouldn't it be better if we just put free pens on every street corner? And think of all the toll booths that impede the flow of traffic. It's a gigantic social phenomenon. People find ways of getting money by impeding society. Once they can impede society, they can be paid to leave people alone. The waste inherent in owning information will become more and more important and will ultimately make the difference between the utopia in which nobody really has to work for a living because it's all done by robots and a world just like ours where everyone spends much time replicating what the next fellow is doing.

BYTE: Like typing in copyright notices on the software. Stallman: More like policing everyone to make sure that they don't have forbidden copies of anything and duplicating all the work people have already done because it is proprietary.

BYTE: A cynic might wonder how you earn your living. Stallman: From consulting. When I do consulting, I always reserve the right to give away what I wrote for the consulting job. Also, I could be making my living by mailing copies of the free software that I wrote and some that other people wrote. Lots of people send in $150 for GNU EMACS, but now this money goes to the Free Software Foundation that I started. The foundation doesn't pay me a salary because it would be a conflict of interest. Instead, it hires other people to work on GNU. As long as I can go on making a living by consulting I think that's the best way.

BYTE: What is currently included in the official GNU distribution tape? Stallman: Right now the tape contains GNU EMACS (one version fits all computers); Bison, a program that replaces YACC; MIT Scheme, which is Professor Sussman's super-simplified dialect of LISP; and Hack, a dungeon-exploring game similar to Rogue.

BYTE: Does the printed manual come with the tape as well? Stallman: No. Printed manuals cost $15 each or copy them yourself. Copy this interview and share it, too.

BYTE: How can you get a copy of that? Stallman: Write to the Free Software Foundation, 675 Massachusetts Ave., Cambridge, MA 02139.

[In June 1995, this address changed to: Free Software Foundation 59 Temple Place - Suite 330 Boston, MA 02111-1307, USA Voice: +1-617-542-5942 Fax: +1-617-542-2652 -gnu@prep.ai.mit.edu ]

BYTE: What are you going to do when you are done with the GNU system? Stallman: I'm not sure. Sometimes I think that what I'll go on to do is the same thing in other areas of software.

BYTE: So this is just the first of a whole series of assaults on the software industry?

Stallman: I hope so. But perhaps what I'll do is just live a life of ease working a little bit of the time just to live. I don't have to live expensively. The rest of the time I can find interesting people to hang around with or learn to do things that I don't know how to do.

Editorial Note: BYTE holds the right to provide this interview on BIX but will not interfere with its distribution.

Richard Stallman, 545 Technology Square, Room 703, Cambridge, MA 02139. Copyright (C) 1986 Richard Stallman. Permission is granted to make and distribute copies of this article as long as the copyright and this notice appear on all copies.

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