What is the class Object? What is the class Class? Why the class Object is an instance of the class Class? If you ever ask yourself such questions, this book is for you. After explaining the impact of representing classes as objects, you will develop step by step a minimal reflective kernel. In this book you will learn: - object instantiation, allocation, and initialization, - classes as objects, - description of classes, - creation of classes, - method lookup and error handling, - examples of metaclasses, - bootstrap of a reflective system. The content of this book has been used to teach reflective architectures for more than 15 years.