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.
