From Object-Orientation to Formal Methods

After Ole-Johan's retirement at the beginning of the new millennium, some of us had thought and talked about making a "Festschrift" in his honor. When Donald Knuth took the initiative by sending us the ? rst contribution, the p- cess began to roll! In early 2002 an editing group was formed, including Kristen Nygaard, who had known Ole-Johan since their student days, and with whom he had developed the Simula language. Then we invited a number of prominent researchers familiar with Ole-Johan to submit contributions for a book hon- ing Ole-Johan on the occasion of his 70th birthday. Invitees included several members of the IFIP 2. 3 working group, a forum that Ole-Johan treasured and enjoyedparticipating in throughouthis career. In spite of the shortdeadline, the response to the invitations was overwhelmingly positive. The original idea was to complete the book rather quickly to make it a gift he could read and enjoy, because by then he had had cancer for three years, and his health was gradually deteriorating. Kristen had been regularly visiting Ole-Johan, who was in the hospitalat that time, and they were workingon their Turing award speech. Ole-Johan was grati? ed to hear about the contributions to this book, but modestly expressed the feeling that there was no special need to undertake a book project on his behalf. Peacefully accepting his destiny, Ole- Johan died on June 29, 2002.

A Biography of Ole-Johan Dahl. - A Bibliography of Ole-Johan Dahl. - The Birth of Object Orientation: the Simula Languages. - An Algebraic Theory of Actors and Its Application to a Simple Object-Based Language. - Towards Posit & Prove Calculi for Requirements Engineering and Software Design. - Distributed Concurrent Object-Oriented Software. - Composing Hidden Information Modules over Inclusive Institutions. - Towards the Verifying Compiler. - Object-Oriented Specification and Open Distributed Systems. - SIMULA and Super-Object-Oriented Programming. - Efficient Coroutine Generation of Constrained Gray Sequences. - Consistency of Inheritance in Object-Oriented Languages and of Static, ALGOL-like Binding. - The Power of Abstraction, Reuse, and Simplicity: An Object-Oriented Library for Event-Driven Design. - Iterative Synthesis of Control Guards Ensuring Invariance and Inevitability in Discrete-Decision Games. - Incremental Reasoning for Object Oriented Systems. - Pure Type Systems in Rewriting Logic: Specifying Typed Higher-Order Languages in a First-Order Logical Framework. - Building Optimal Binary Search Trees from Sorted Values in O(N) Time.