This chapter begins a departure from the previous chapters in the book. Previously, the chapters concentrated heavily on the Node.js core and its functionality. This was to build a better understanding of the fundamental architecture and platform availabilities that are included with Node.js. However, Node.js is a thriving success because of the ecosystem of third-party modules and the extensibility that they provide. This chapter, and those that follow, will provide you will a taste of the Node.js community and what it can offer you in your application development. This chapter begins by discussing WebSockets.