We've got most of the pieces of our application stack in place now. We have a runtime environment, Node.js. We've installed and set up a web application framework, Express. We just set up our database, MongoDB.
The one piece that's missing is pretty crucial in any SPA—no matter what the backend stack looks like, there's a frontend framework to make the SPA magic happen.
There are numerous frontend libraries and frameworks used for SPAs, but one of the most popular, and the A in MEAN, is AngularJS, otherwise known as Angular.
Angular is an open source frontend framework, particularly well-suited to building SPA. It's extremely popular and currently maintained by Google.
Note
In this book, we will use AngularJS version 1.4.8, which was released in November, 2015. AngularJS 2.0 was announced in 2014 and is, at the time of publication, just made available in a production version. The 2.0 version introduced breaking non-backward-compatible changes. Most development today is...