From the book's author:

I am giving away this first version of the book for free. I do reserve the right to print the book and sell it. You are free to distribute the pdf file or print it. You are also free to distribute printed copies, but you may not get paid for it.

Feel free to use the code samples, either as they are or as inspiration for your own work. Attribution would be nice, but isn’t required.

I will be grateful for feedback, and do so at the Github page for the book – or by email to the address shown in the book. I intend to publish a revised version of the book if I receive feedback that warrants an update.



More about the book on here.