A section of the utils.common.js file uses code from 
the book:

"JavaScript: The Good Parts by Douglas Crockford"
"Copyright 2008 Yahoo! Inc.,978-0-596-51774-8."

Here are the relevant sections from the book's preface
First Edition May 2008. Preface pages 1, 2.


P2.2. Using Code Examples

This book is here to help you get your job done. In general, you may use the code in this book in your
programs and documentation. You do not need to contact us for permission. For example, writing a program
that uses several chunks of code from this book does not require permission.


We appreciate, but do not require, attribution. An attribution usually includes the title, author, publisher, and
ISBN. For example: "JavaScript: The Good Parts by Douglas Crockford. Copyright 2008 Yahoo! Inc.,
978-0-596-51774-8."