This book introduces Modula-2 through an object-oriented programming approach which has been developed over the past five years on the BSc and MSc computer science courses at Hatfield. Chapter 1 introduces the main features of Modula-2 through an example program, whilst chapter 2 introduces the concepts required for object-oriented program design. All the essential high level features of the language are covered in some detail in chapters 3 to 8. Chapter 9 explores the main attributes of an object-oriented language and considers to what extent these features are represented in Modula-2. Chapters 10-12 develop object-oriented solution to simple example through the implementation of some of these features. The low level features of the language are discussed in chapter 13, and chapter 14 extends these features to discuss the implementation of basic operating system functions in Modula-2. This book is suitble for beginners in programming following an undergraduates in computer science and as self-study text for more experienced high-level language programmers who wish to learn Modula-2 in the context of an object-oriented approach. We recommend read and implement the example program in chapter 1 then read chapter 2 to obtain a flavour of object oriented design; however they should leave a full study of the example program in chapter 2 until they have become fully familiar with the material in chapters 3 to 8. The more experienced programmer may not need to implemten the program in chapter 1 but should carefully study the example in chapter 2 where a distinction between more traditional functional decomposition and the object-oriented approach is explored in some detail.