While there are many books on particular languages, there are very few that deal with all aspects of object-oriented programming languages as they currently stand. The Interpretation of Object-Oriented Programming Languages provides a comprehensive treatment of the main approaches to object-oriented languages, including class-based, prototype and actor languages.This revised and extended edition includes:- a completely new chapter on Microsofts new C# language, a language specifically designed for modern, component-oriented, networked applications. The chapter covers all aspects of C# that relate to object-oriented programming. - a new appendix on the BeCecil language, an extensible research language based on the prototypes concept. BeCecil is a kernel language that can implement object-oriented constructs within a single framework; BeCecil shows how OO concepts can be reduced to a common semantic core.This book will be useful for final year undergraduates/first year postgraduates studying object-oriented programming, as well as research students and other requiring a detailed account of object-oriented programming languages and their central concepts.