The systematic development of software systems is a central task of computing science. A software system is the result of putting together knowledge about the application, requirements and structures of computing science. This collection of papers presents examples of a formal approach to programming language concepts and program development, based on algebraic specification and program transformations. Examples are also presented of the evolution and modification of the original ideas of a project known as CIP (Computer-Aided Intuition-Guided Programming). The topics range from descriptions...