Whether you're reading this online, or in a book, welcome to our collection of notes about operating systems development! We've written these while writing (and re-writing) our own operating systems, with the intent of guiding a reader through the various stages of building an operating system from scratch. We've tried to focus more on the concepts and theory behind the various components, with the code only provided to help solidify some concepts. We hope you enjoy, and find something interesting here! This book is a printed version of the notes avaiable here: https://github.com/dreamos82/Osdev-Notes