Ken Iverson

R.I.P. Ken Iverson

Ken Iverson died October 19, 2004 at the age of 83.

Dr. Kenneth E. Iverson is the father of the AplLanguage, and more recently the J language(JayLanguage). He was an IBM fellow, and is a gifted mathematician, educator, and writer.

His latest publication, "MathForTheLayman" is now available at

He received the ACM TuringAward in 1979:

For his pioneering effort in programming languages and mathematical notation resulting in what the computing field now knows as APL, for his contributions to the implementation of interactive systems, to educational uses of APL, and to programming language theory and practice.

See also ...


December 17, 1920 APL Co-Inventor Iverson is Born.

Kenneth E. Iverson is born in Camrose, Alberta, Canada. He received a BA in mathematics from Queen's University in Ontario, a MA and PhD in applied mathematics from Harvard. Iverson taught at Harvard, worked for IBM and I.P. Sharp Research Associates. With Adin D. Falkoff, he developed A Programming Language (APL). It was a triumphant start of his career, and for over 35 following years Iverson was able to transform his invention into a successful commercial property. He received the AFIPS Harry Goode Award in 1975, ACM Turing Award in 1979, IEEE Computer Pioneer Award in 1982, and the National Medal of Technology in 1991.

This quote from "APL/360 An Interactive Approach" is informative.

I was told that Ken developed the language to simplify the use of mathematical symbology (For example, the use of capital Sigma and Pi to represent the sum and product of a series, respectively, was replaced with '+/' and 'x/' or any other binary mathematical operator.)

Ian Sharp told me that Ken had originally developed the notation to simplify the teaching of algebra to students.

Larry Breed, Roger Moore and Dick Lathwell were awarded a Grace Hopper prize for the subsequent implementation of the notation as a programming language.

I.P. Sharp (see also: IpSharp (BTW, not I. P. Sharp Research Associates)) used it to sell timesharing services, based on a 360/50 that could support more than 100 concurrent users, in spite of the hardware's architectural restrictions with respect to initiators and memory.

-- HansWobbe


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