letters to the editor
DOI: 10.1145/1435417.1435420
true seeds of open source software

Though I apprecIated Martin

Campbell-Kelly’s “Vie wpoint”

“Will the Future of Software

Be Open Source?” (Oct. 2008),

we must still rectify a small

piece of history to apportion credit cor-

rectly. Campbell-Kelly asserted that fol-

lowing the release in 1964 of the IBM

System/360 as a “standard computer

platform” the software world experi-

enced a radical transformation. How-

ever, the S/360 followed by a year the

Burroughs B5000, a far more capable

system; its successor, the B5500, came

out only six months after the S/360.

The B5000 took an integrated ap-

proach to hardware and software; its

architecture deliberately supported

development of software exclusively in

high-level languages, mainly ALGOL-

based. This was at a time when the rest

of the world thought a language like AL-

GOL could not be implemented. (Don-

ald Knuth implemented a Burroughs

ALGOL compiler on the B205 during

a three-month summer vacation.) The

rest of the world did not, alas, figure out

ALGOL for a long time, and eventually

adopted a far-less-capable language—

C—as a systems programming lan-

guage. In his technical report “Hints on

Programming Language Design” C. A.R.

Hoare said, “Here is a language so far

ahead of its time that it was not only an

improvement on its predecessors but

also on nearly all its successors.” The

same can be said of the B5000.

All B5000 system software was dis-

tributed in source form, and users

could read and modify it and submit

patches back to Burroughs. Because it

was all written in ALGOL-like high-lev-

el languages, source distribution was

even more meaningful than if it was

in cryptic assembler, as in the S/360.

Hence, the B5000 contained the seeds

of open source software.

Edsger Dijkstra’s reaction is also

telling; he said the week he studied

the specifications of the S/360 was the

“darkest week in my professional life.”

He later became a research fellow at

Burroughs. The B5000 also had a tagged

polymorphic (object-oriented) archi-

tecture designed by Robert Barton, who

went on to influence Alan Kay and oth-

ers in his object-oriented thinking.

The Burroughs B5000 not only pre-

dated the S/360 but reflected a far more

radical transformation in software de-

velopment. The S/360 was a huge back-

ward step compared to other develop-

ments, especially the B5000, which

lives on today in Unisys MCP systems.

ian Joyner, Sydney, Australia

campbell-Kelly responds:

Burroughs was indeed a highly innovative computer manufacturer and never achieved the sales it deserved. At the time of the S/360 launch in 1964, IBM already had over 80% of the mainframe market, compared with Burroughs’ modest 4%. Despite the B5000’s superb architecture and software system, the S/360 became the standard platform adopted by the great majority of computer centers worldwide.

martin campbell-Kelly, Coventry, u.K.
cs as Related to Philosophy
as it is to nature

When I decided in 1984 to make teaching computer science my career, I was strongly motivated by the interconnections among CS, nature, and philosophy that have subsequently guided my approach to teaching. The “Review Article” “The Many Facets of Natural Computing” by Lila Karl and Grzegorz Rozenberg (Oct. 2008) described theoretical and experimental research that put flesh on our deepest intuition about the interdisciplinary nature of CS and thus laid a solid foundation for a computational view of nature in the CS curriculum. In this light, please consider the following anecdotal comments:

Nature as inspiration. As a young programmer in the early 1960s, I began pondering the relationship between parallel processing and the multitasking capabilities of early operating systems with our own human executor; we multitask at will, even as parallel processes run within us;

Information processing in nature. It

seemed intuitive that information processing (such as genes and evolution) would take place in living things, but how about in nonliving things? For example, when two molecules combine to form a new molecule, do they exchange information? What even is information? The word’s etymology suggests it is related to structure. So do two molecules have to be structurally “ compatible” before they are able to combine?;

Pleasant surprise. I was a graduate student at the University of Colorado at the time professor Andrei Ehrenfeucht was collaborating with the author Rozenberg. Their theoretical research concerned how to model plant growth through formal grammars; I was in awe of their effort to try to unlock a deep mystery—a language of nature;

CS and philosophy. I invite computer
scientists to consider how closely CS
is related to philosophy, as well as to
natural science. Philosophy contrib-
utes to CS, despite sometimes conten-
tious disputation. Two examples are
Frege’s invention of first-order logic (he
was, by his own account, equal parts
philosopher and mathematician) and
Austin’s and Grice’s contributions to
natural language processing research.
CS may likewise prove useful for phi-
losophy. The concept of undecidability
(and the use of “proof by contradiction”
as a proof tool in undecidability argu-
ments) may be useful in resolving long-
standing philosophical problems; and
Philosophical intuition. The structure
theorem of programming says that any
(proper) program might be described
using (only) control structures for se-
quence, selection, and iteration. My
intuition tells me that when a program
refers to the real world, sequence refers
to time, selection to (finite) choice, and
iteration to inertia.
As one who loves CS and its deep
connections to nature and philosophy,
I say to the authors Karl and Rozenberg,
Thank You and Hooray!
nicholas ourusoff, new London, nH

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