This book is a comprehensive programming guide for the Java Virtual Machine (JVM). It gives the reader a strong overview and reference of the JVM so that they may create their own implementations of the JVM or write their own compilers that create Java object code. Perhaps the most important reason for learning about the Java Virtual Machine is that it gives you additional tools for solving programming problems in Java. The Java architecture is very open -- its easy to add programatic extensions to Java, once you have learned the basic rules of the Java Virtual Machine. And the Java Virtual Machine is portable, so you only have to write the extension once. So if you don"t like how a particular feature of the Java language works, why not create an extension library which operates in the way you need it to? Its not as hard as you might think, and this book gives you all the details you need.