The "Java Developer's Reference" covers essential topics for Java developers, including installation, language basics, and debugging. It also discusses Java for programmers familiar with C++ or Visual Basic, as well as developing applets and applications. The reference guide explores using Java packages and documenting programs with JavaDoc. It provides insights into troubleshooting Java installations and utilizing tools like Javac, JDB, and HTML for Java programmers. The goal is to help developers understand and utilize Java effectively, whether they are beginners or experienced programmers.