The new release of AngularJS, simply known as Angular, is a complete rewrite of the previous one, entirely based upon TypeScript and ECMAScript 6 specifications.

The choice of not making Angular backward compatible with AngularJS clearly demonstrates the intention of the author's team to adopt a completely new approach--any developer who already knows AngularJS will undoubtedly face a huge number of breaking changes, not only in the code syntax, but also in the way of thinking and designing the client app. Angular is highly modular, component-based, comes with a new and improved dependency injection model and a whole lot of programming patterns its older cousin never heard of.

However, the most important reason we're picking Angular over other excellent JS libraries such as ReactJS and EmberJS is the fact that it already comes out with a huge pack of features out of the box, making it most suited, although maybe not as simple to use than the aforementioned competitors; if we combine that with the consistency given by the TypeScript language, we can say that despite being the youngster, Angular embraced the framework approach more convincingly than the others. This has been confirmed over the course of the past 9 to 12 months, where the project hit two major versions (Angular 2 in Q3 2016 and Angular 4 in Q1 2017), gaining a lot in terms of stability, performances, and features, without losing much in terms of backward compatibility, best practices, and overall approach. All these reasons are solid enough to invest in it, hoping it will continue to keep up with these compelling premises.