Pharo is a dynamic object-oriented programming language. Pharo's model and syntax are uniform, simple and expressive. These properties, when added to a powerful and flexible programming environment, regularly attract new developers. The community around Pharo has been steadily increasing over the years. This community is actively creating exciting and innovative software artifacts helping the development of advanced software systems. Pharo heightens the software building experience to its best. It offers open and object-oriented programming environments and libraries. The book covers a large spectrum of topics ranging from central language aspects to innovative frameworks and libraries. This book contains unique material often presented in a tutorial form with many hand-on exercises. Everybody will learn something reading this book: programmers familiar with Pharo will enjoy the highlights made of some particularly beautiful aspects of Pharo as well as discovering new and powerful frameworks. Practitioners making their debut with Pharo will take on a wonderful journey in the realm of objects. Deep into Pharo presents both internal aspects of Pharo and libraries that prove to be important for academic, business and development perspectives.