Seibel: Was the domain of speech recognition not that interesting or was it something about the programming involved?

Ingalls: Oh, it was interesting—it was fascinating. I ended up building up a whole personal-computing environment on this Sigma 3 minicomputer. It used card decks and Fortran was the main thing I had to work with. Out of that I built an interactive environment. I wrote a text editor in Fortran and then something so we could start submitting stuff remotely from a terminal. It wound up being a nice little computing environment, just done in this sort of strange way.

Seibel: This desire for an interactive environment is a theme that’s come up a bunch of times in your career. For example, you wrote the first Smalltalk in BASIC because that was the interactive environment you had at hand. Where did you get that idea that given a problem to solve, the first thing you need is an interactive programming environment?

Ingalls: That’s a good question. I think anything where you get immediate gratification feeds on itself by definition.

Seibel: So what was that first place that you had that immediate gratification?

Ingalls: There were a couple of experiences. I had a chance to work with a semi-interactive PL/I. And a friend of mine was working at an IBM where they had an interactive APL environment. I can’t remember which of those was first. I really remember the APL one. That affected me in a number of ways because of both the immediacy of interaction—seeing your results come back—and the expression evaluation, which is really different from Fortran’s statement-oriented programming.

You still see that now, it’s amazing—the whole C/C++/Java tradition, although it goes in an object-oriented direction, is still statement-oriented. But if it’s convenient to make expressions, it really makes the experience different. To me it brings the mathematics to life more. Anyway, it was one of those two. When I got to Xerox there wasn’t much interactive except the Lisp guys’ stuff. I happened not to be into Lisp. Things would have been different if I were, I expect.

Seibel: How so?

Ingalls: I think I would have gone completely in that direction. And by not having gone in that direction, it left me wanting to do that kind of thing in a different way. I think what I worked on with Alan had that same kind of nice, lively, expression feel, but it included the notion of objects and messages more naturally.

I think if I had been as comfortable in a system like Lisp, I never would have bothered. I would have tried working around it to get objects, but starting with the notions of objects from the get-go and then making that nice and interactive and convenient was, I think, a contribution.

Seibel: Alan Kay has said that both Lisp and Smalltalk have the problem that they’re so good they eat their children. If you had known Lisp, then Smalltalk would have been the first eaten child.

Ingalls: Maybe so.

Seibel: So that’s a nice example of the advantage of some ignorance; it leaves some room for creativity. But sometimes it feels like ignorance is endemic in this industry—that people are unaware of things and wheels are constantly being reinvented with pointy corners.

Ingalls: That’s true.

Seibel: Should we be trying to fix that? Is it just a price that we have to pay so that people can have room for creativity? Or would we be better off if people were a little more aware of what else is going on?

Ingalls: I’m an embrace-diversity guy. The example we just went through, I think, says, “No, let people go whatever way they want.” There will be waste from ignorance, but natural selection will take care of straightening things out. And you will get these occasional sports that take you into the future.

I can think of lots of areas where trying to standardize, trying to all go in one direction, has suppressed creativity. I work at a company that’s supported by Java, so I’m not going to go very far with this, but it is the case that when Java came out—the easiest way I had of measuring it was looking at what went on at OOPSLA—when Java came out not only did work slow down and even maybe come to a halt on other object-oriented programming languages but even in dynamic programming in general. I think that was a loss.

But it wasn’t permanent. People finally realized “Oh, wait a minute, Java has all these great strengths and we’re using it for this and that but we were on to other good things with dynamic programming languages and it’s time to get back to that.” But that’s an example that’s easy for me to see because I’m involved in it.

In a much bigger sense I hate to see computer-science departments that feel their role is to prepare people to work in an industry and the industry is going that way and therefore we have to teach our students that way. It’s exactly the wrong thing to do. What you should be doing with your students is teaching them to think generally—think outside the box and plot the other courses we should be pursuing.

It’s not a simple problem because there is great value to having that whole standard out there. Having thousands of programmers who have worked on thousands of routines and they’re very solid—you can get your work done that way.

It’s a little bit the difference between computer science in the service of production and computer science in the service of moving the intellectual content forward. I’ve been having fun with the Lively Kernel, which is, in a way, trivial. There’s nothing new about it—I’m using all stuff that was there before. It’s built on JavaScript and the graphics you can get in a browser. But it’s been really fun because it’s another kernel like Squeak. Because JavaScript is all there in the browser and the graphics is all there in the browser, the work on the kernel is very tiny. It’s just, how do you bring the graphics to life and how do you build up a little computing environment.

Whenever you do something like that, small enough, then anybody can understand it. If you take a few things out of the equation, like the language and the graphics, then the question is, what is the kernel? And I think that’s an interesting question.

I’m hoping that this—not particularly my stuff—but this kind of investigation might reinspire computer science to do some studies about how do you make a kernel, what other kernels could we build that are even simpler, even more uniform.

It’s like what math did. Math found by symbolizing things that you could simplify a lot of stuff. Then, because of that, you could start to think about bigger constructs. That’s my hope.

Seibel: When you say a kernel, you’re talking about a programming kernel. What’s the core of the Lively Kernel?

Ingalls: What I mean by a kernel, typically, is you put together enough stuff that it can, in some sense, build itself or build other useful things. Squeak is one that really can build itself. The Lively Kernel presumes the existence of JavaScript and some graphics, but it ends up with the ability to edit the graphics so that you can make new graphical things and to edit the programs so you can make new programs. So it’s enough to build all the applications that you might want to build in a browser.

I think in playing this game you get to hide layers that you want to. The question is, where is your playing field. In Squeak the whole language is part of the kernel so it’s got its own compiler and byte-code interpreter. And it’s got its whole graphics system—it’s got BitBlt and all the stuff around that.

It looks like those are an important part of any kernel but you can take them out. You can say, “Let’s assume that we have a dynamic language; let’s assume that we have graphics.” In my old thinking, I would have thought, “Well, there is nothing else.” But it’s not true. What’s left is, how do you put the graphics together to make an interesting user interface environment? And how do you bring programs and scripts up to the level that you can change them?