This book is released under the Creative Commons Attribution-NonCommercial-ShareAlike License 2.0.
Basically, you are free to copy, distribute and display the book, as long as you give credit to me. The restriction is that you cannot use the book for commercial purposes without my written permission. You are free to build and modify upon this work, provided that you clearly mark all changes and release the modified work under the same license as this book. Please visit the license page for exact details.