This volume provides an account of the current state of the theory of combinatory spaces and discusses various applications. Here the term `combinatory space' can be regarded as a system for functional programming, and bears no close connection with combinatory logic. The main text is divided into three chapters. Chapter 1 deals with computational structures and computability; Chapter 2 considers combinatory spaces; and Chapter 3 embraces computability in iterative combinatory spaces. A number of appendices treat a survey of examples of combinatory spaces. All sections of the various chapters contain exercices togethers with hints for solution where appropriate. For the reading of some parts of the book a knowledge of mathematical logic and recursive function theory would be desirable. For researchers and specialists in mathematical logic and its applications and theoretical computer scientists.