algol actor model algorithm association for computing machinery bcpl bjarne stroustrup bob bemer computer file computer graphics computer program concurrency coroutine data type discrete event simulation enea ab education error for loop hello world program ieee john von neumann medal implementation international federation for information processing kristen nygaard norwegian computing center oopsla object-oriented programming object-oriented programming language ole-johan dahl oslo process programming language programming language implementation programming paradigm runtime simula research laboratory simulation simulation language smalltalk source code syntax system turing award typesetting univac university of oslo very-large-scale integration virtual function