On the teaching of programming, i.e. on the teaching of thinking -- Parallel programming: An axiomatic approach -- On-the-fly darbage collection: an exercise in cooeration -- An exercise in proving parallel programs correct -- The programming language concurrent pascal -- Guarded commands, non-determinacy and a calculus for the derivation of programs -- Program production by successive transformation -- Programming as an evolutionary process -- Proof of correctness of data representations -- A philosophy of programming -- The structure of an operating system -- Language aspects in operating systems -- Structured programming in the basic layers of an operating system -- A time-wise hierarchy imposed upon the use of a two-level store -- Problems in many-language systems.