Java is a new object-oriented programming language that was developed by Sun Microsystems for programming the Internet and intelligent appliances. In a very short time it has become one of the most widely used programming languages for education as well as commercial applications. Design patterns, which have moved object-oriented programming to a new level, provide programmers with a language to communicate with others about their designs. As a result, programs become more readable, more reusable, and more easily extensible. In this book, Matthias Felleisen and Daniel Friedman use a small subset of Java to introduce pattern-directed program design. With their usual clarity and flair, they gently guide readers through the fundamentals of object-oriented programming and pattern-based design. Readers new to programming, as well as those with some background, will enjoy their learning experience as they work their way through Felleisen and Friedman's dialogue.