1. Introduction

This is the reference manual for the Geant4 toolkit. It describes definitions of all classes and their public methods which are necessary for Geant4 application developers.

Chapter 2 explains C++ code convention used in the Geant4 toolkit. It also includes programming suggestions learned from experience of the Geant4 development.

Chapter 3 describes, class category by class category, the definitions of classes in it and their public methods. It covers all classes necessary for those who want to develop a detector simulator using Geant4. This means it does not contain entire classes in the Geant4 toolkit. Suppose if you want, as a toolkit developer, to develop an additional functionary to the toolkit, probably you need to read directly the source codes instead of reading this reference manual.