In this chapter, we got acquainted with Knockout.js, what it is what its benefits are, how to download and install it, and how to write a simple "Hello World" application. In addition, we covered the MVVM design pattern and how it helps us to build a nice application with the help of Knockout.js. The Hello World example demonstrates basic Knockout.js features, such as observables, data bindings, subscribing logic, and its extenders.