April 10, 2001

From Amsterdam to Alabama with FOX creator Jeroen van der Zijp

Author: JT Smith

- By Julie Bresnick -

Open Source people -
Jeroen van der Zijp's official job title at CFD Research Corporation, where he
works on
scientific data visualization, is so general that it sounds more like a
description than a function. It is so void of affect that it would
perfectly normal were it to be overheard in conversation that say, his
grandmother might have with one of the other members at a senior
"Oh that grandson of mine, he's such a technical fellow." That's it,
the title is "technical fellow" (a management-track title for techies). It could probably be used to describe a large
portion of
the roughly 2,000 original visitors to the Web site set up for FOX, the GUI toolkit he
building as a hobby in March 1997.

"TV was lousy," he laughs, accentuating the casual nature of FOX's
beginnings, "and I had tired myself of Motif." His
is burdened with a strong Dutch accent that at times sounds, maybe
of the Alabama accent he has been surrounded by for the last 14
surprisingly Scottish. Van der Zijp was 25 when he followed a
professor to Huntsville, Ala., where, he settled in to complement his
bachelor's degree in computer science with a Ph.D. from the University of Alabama, Huntsville.

Originally, upon embarking on his undergraduate work at the University of Amsterdam, his focus
on physics. But as his instructors had warned right before they
teaching his class Fortran, the first taste of programming was enough
stimulate the switch to computer science. Physics, computer science,
didn't matter, van der Zijp was always figuring things out ever since he was
little kid. Taking things apart, putting them back together, messing
clocks, he had indeed always been a rather technical fellow, a tendency
accelerated after he first learned to tinker with a TI 58 programmable
calculator. Now he's 39, but it was during his first year of college, at age
that he first used a computer.

"It was another time. You should not forget, this was the
His grammar is still affected by that of his mother tongue. "If it
cost x
here it costs 2x over there. Rich people had Apples, but we had to do
other things and, of course, there was the mainframe in the basement of
university. That was an experience. It's punch cards and stuff. I
GUIs were probably nicer way to work with computers. Punch cards, I
remember it well. Basically you submit your job and you, well, you
coffee for half an hour and then the output comes out and it turns out
forgot the semi-colon.

"First, second year, we got a Fortran course and Pascal also, so
I did a lot of stuff in Pascal. C was not really being used at all
actually, we had Pascal and actually the extended Pascal for the
data machines. Once I found out about Pascal, I dropped Fortran like a
I very quickly discovered that Pascal was way better."

Most of FOX, which is almost entirely platform independent, is
written in

"After messing with foundation classes, I sort of gave up on it and
started writing my own little wrapper library. I did the same for
Motif, so
basically you could say FOX has two sort of pre-cursors that crashed
burned, from which I learned a great deal. The basic idea with FOX is
it's not a wrapper around some existing tool kit. There are some GUI
libraries that basically use motif when they are on Unix and they use
Windows when they are on Windows. I decided that was essentially too
trouble [because] you end up doing some kind of lowest common denominator
If Windows doesn't have it, then you have to make a decision that if
this is
supposed to be portable, then you have to limit yourself to what
the intersection of both machines have. So I thought to myself, 'you
this can't ever work.' So I made the decision to go all the way down,
go to
the lowest level facilities like drawing lines and getting input from
mouse and keyboard. At that level everybody more or less has the same
functionality and everything else is written in my own C++ code. And so
that's fairly fundamental, because it means it not only behaves exactly
same on all machines but it also looks exactly the same on all

Its appearance, much to the reluctance of van der Zijp himself, is
similar to that of Windows.

"I make it look like Windows. This is sort of a strategic decision
that a lot of people don't think that it is a real GUI if it doesn't
like Windows. I hear this very often. Some packages I've seen and the
comments you hear behind you is, 'it looks a little bit clunky doesn't
And that's just because, to the manager types, it's not a real thing
it looks like Windows. I think FOX will not look like Windows

To van der Zijp, Open Source is no big revolution, it's simply the way.
been on the Internet since there was Usenet. He's been sharing code since
learned how to write code. But as FOX has grown, van der Zijp's paternal
perspective has granted him an even greater appreciation of the value of Open Source.
his company decided to employ the FOX library, van der Zijp's instincts told
him to
ensure that its source remained open. Hindsight has emphasized
importance of that priority.

"Major contributions have been made by people outside of the
These contributions range from hosting mirror sites, to bug reports, to
source code and ideas. People all over the world have not only shown
interest, but also that my work has been intensely scrutinized, almost
line of code has been under the microscope. The result is that this
made the FOX library a much better GUI toolkit than it would have been
otherwise. Indeed, I think it would have probably withered on the vine
it had been made proprietary.

"You may not be able to make money *selling* [free software] but you
surely make, or save, by *using* it! In our [CFD Research Corp.] case,
could have continued to use Motif, and run on Windows using the eXceed
X-Windows emulator, but software development has been dramatically
because FOX takes about one-tenth the amount of code for the GUI
development, and also some money was saved by eliminating the need for
eXceed package which was needed under Windows. Also, debugging and
testing has been reduced, because we can use a single GUI library across
the supported platforms while Motif implementations varied greatly
the different work-stations."

It is also the community development approach that stimulated and
spearheaded FOX's evolution into versatility and independence.

"Although I have personally ported FOX to many machines -- SGI, DEC,
SUN, IBM, and PCs running Windows or Linux -- more configurations are
being added, like FreeBSD, for example. I do not have this myself, but
people donate
the necessary changes to the project."

Van der Zijp's perspective on the growth of FOX is notably humble. In
to the orchestrated nature of the Open Source marketing campaign,
van der Zijp
speaks of FOX as if its popularity were a product of happenstance. Yet
appears to be making significant headway in one of the creator's

"What's sometimes a bit surprising, is that some people are starting
use it as a replacement for Windows-only development (these people
previously have been using things like Microsoft Foundation Classes or
Borland C++ or something like that.) Apparently, the GNU compiler and
make a nice combination for Windows development for a very low cost."

It seems that FOX, enjoying significant growth as a result of a
completely organic process of community development, no significant
marketing or promotion, just peer review and donated mindshare, may yet
emerge as one of the purest cases for the promotion of Open Source.

About Jeroen van der Zijp

Born: Amsterdam, Netherlands.

Raised: Just north of Amsterdam in Krommenie.

Degrees: B.A. in computer science from the University of Amsterdam,
in computer science from the University of Alabama in Huntsville.

Thesis: Analysis and Visualization of Supersonic Flow Interferometry
old physics thing reared its ugly head.")

First computer: "A SIM 1 with a whopping 4 KB of RAM in it. You had to
program it with a Hex display. It had 16 keys."

Pride and Joy: 1 ½- year-old daughter Ady.

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