Ole-Johan Dahl ACM Turing Award (2001) Presentation by Carsten Hood CSCE | Spring 2014

Life | Ole-Johan Dahl  Born in Norway in 1931  Received his MS in Numerical Mathematics at the University of Oslo in 1957  In 1952 began mandatory military service at the Norwegian Defense Research Establishment and was introduced to computers and Kristen Nygaard.  Joined the Norwegian Computing Center from 1963 to 1968  Became a full professor at the University of Oslo in 1968

Partnership with Kristen Nygaard  Dahl immediately befriended fellow Norwegian computer scientist Kristen Nygaard at the Defense Establishment.  This relationship combined two intelligent minds with different backgrounds  Together they developed the SIMULA programming language.  They remained lifelong friends and partners. Without the unique brilliance of this partnership, the concepts of object-oriented programming may have taken much longer to emerge.

The SIMULA Language  Based on the well-known language ALGOL 60  First object-oriented programming language  Intended as a means of writing simulation programs for the military and industry.  Generalized in SIMULA 67  Originated the concepts of objects, classes, inheritance, and modularity  Included virtual methods, active objects, action combination, processes & schedulers, frameworks, automatic memory management & garbage collection  SIMULA 67 was an ancestor of C++, C#, Smalltalk, and Java

Contributions | Ole-Johan Dahl  Considered a co-founder of object-oriented programming  Singlehandedly developed the computer science college at the University of Oslo  As a professor researched systems of reasoning mathematically about OO systems and computer programming  Contributed to the important book Structured Programming, published in 1972  Later helped to develop the Advanced Boolean Expression Language (ABEL)

Legacy | Ole-Johan Dahl  Remained loyal to his country and alma mater throughout his life.  Helped invent one of the most important programming paradigms  Known for his modesty; attributed much of his revolutionary ideas to luck  Received the Turing Award with Kristen Nygaard for his work on SIMULA and object-oriented programming in 2001  Ole-Johan Dahl passed away the summer of His colleague Edsger Dijkstra died the next week; partner Kristen Nygaard died the week after.