I'm a fan of Eloquent JavaScript. In my book on CoffeeScript (http://pragprog.com/titles/tbcoffee/coffeescript), I recommend it as a resource for readers who want a thorough introduction to JavaScript. So obviously, I think it's pretty damn cool that someone ported his book to CoffeeScript (albeit with modified examples). The inclusion of Underscore.js as a standard library is, I think, also quite sensible.

Of course, there's a fundamental philosophical difference between my book and Smooth CoffeeScript, which is highlighted on the book's front page:

> Why no JavaScript? Because it is difficult enough to learn one programming language at a time. This book does not assume knowledge of JavaScript or another language.

I, on the other hand, think that it's important to understand JavaScript in order to work with CoffeeScript, and that CoffeeScript is not well-suited to being a first programming language. The situation will improve as tools for debugging CoffeeScript become available, but even then, it's unlikely that you'll use CoffeeScript for a real project without reading documentation (and code) for libraries written in JavaScript.

But hey, I'm happy to see anything that gets more people hooked on CoffeeScript. :)