An Interview with Paul McJones

In my quest for pioneer programmers I was fortunate to get in touch with one who has a possibly unrivalled record of participation in projects that are important in the development of computing over the decades. I am speaking of Paul McJones, who was part of the team assembled by Butler Lampson to develop Cal TSS, one of the first operating system designs to tackle the problems of protected and even mutually-suspicious subsystems. At IBM San Jose Research he worked with John Backus on his RED languages and with the System R group on the first relational database system. At Xerox he participated in the development of the Star office automation system (based on PARC’s Alto personal computer). Via Tandem Computer he went to do research at DEC SRC in Palo Alto. After various Silicon Valley start-ups he went to work at Adobe. This included a collaboration with Alexander Stepanov. A spin-off of this research is Elements of Programming (by A. Stepanov and P. McJones, Addison-Wesley, 2009), which presents a novel methodology that spans the gap between abstract mathematics and efficient algorithms.

In the following interview we try to cover at least a little bit of this wide and varied terrain.

In Defense of “Beautiful Code”

In my May 2008 APP article “Beauty Is Our Business?” I argued that neither in mathematics nor in programming the concept of Beauty is a useful one. But the B-word is hard to suppress. A kind reader of APP directed my attention to “Beautiful Code: Leading Programmers Explain How They Think”, a collection edited by Andy Oram and Greg Wilson. This book already existed when I wrote my article, so I could have known about it. It’s good that I didn’t, because we now have the benefit of Jeff Atwood’s comments [seen Sept. 30, 2010]. His critique is that an idea can be beautiful, or an algorithm. But the code embodying them is not beautiful, Atwood maintains, and code stands in the way of the appreciation of the beauty of the underlying idea or algorithm. In this article I argue that handwaving is not enough, that such abstract thing as an idea or an algorithm needs embodiment to be appreciated, and that for an algorithm the natural embodiment is in the form of code.