First, I would like to thank the open source community for all the hackers involved in bringing lines and lines of code, documentation, and knowledge into the world. I would like to specifically thank the Samba project team and community! The Samba 4 software is a huge accomplishment and deserves all our appreciation for the effort taken in delivering such a great product. I would like to thank all the editors and reviewers who worked with me during the journey of this book; I would not have been able to do it without your help and invaluable inputs. I would like to thank my family: Ana, Júnior, Pedro, and Leonardo. It's all for you! Last but not least, a big thank you to my grandmother and my mother, Maria Leal. She is the reason I stand here today.