We are living in a time where JavaScript is becoming the most widely-used programming language in the world, even though it is not a language without its faults.

With its rise in popularity, JavaScript has become a legitimate option to develop all aspects of modern applications, applications that comprise a rich HTML/CSS/JavaScript client that communicates with backend services via AJAX. These applications can be run on desktops and mobile platforms as websites, mobile web, or hybrid applications using a native wrapper such as Apache Cordova / Adobe PhoneGap.

Node.js has helped JavaScript reach well beyond the boundaries of the web browser and into our operating systems themselves.

JavaScript, though very successful, can be a difficult language to work with. JavaScript was designed by Brendan Eich in a mere 10 days in 1995 while working at Netscape. As a result, some might claim that JavaScript is not as well rounded as some other languages, a point well illustrated by Douglas Crockford in his book titled JavaScript: The Good Parts, O'Reilly Media.

These pitfalls found in the JavaScript language led Jeremy Ashkenas to create CoffeeScript, a language that attempts to expose the good parts of JavaScript in a simple way. CoffeeScript compiles into JavaScript and helps us avoid the bad parts of JavaScript.

There are many reasons to use CoffeeScript as your development language of choice. Some of these reasons include:

As Jeremy Ashkenas says:

We can use CoffeeScript when working with the large ecosystem of JavaScript libraries and frameworks on all aspects of our applications, including those listed in the following table:

We will look at each of these in depth throughout this book.