How Will REST API Affect WordPress Developers?

With the advent of WordPress 4.4 last year in December, we saw the inclusion of the first half of REST API in the WordPress Core, and the rest of it is expected to be with us in the upcoming major release of WordPress.
That said, REST API has been around us in the WordPress world for quite a while, especially by means of the REST API plugin. The community is abuzz with all talks about how important REST API will soon be for WordPress development, and how it is going to change the way developers code and interact with WP.
So, how is REST API going to affect the WordPress users and developers, and what exactly will we be able to accomplish using it? We will find the answer to this question in this article.

How Will REST API Affect WordPress Developers?
The Rise of JavaScript
Matt Mullenweg made it pretty clear during his State of the Word 2015 address when he declared: “Learn JavaScript, deeply!” With REST API in WordPress, the role of JavaScript in WordPress development will be increased manifolds as HTTP requests and other JSON queries will make good use of JS. With Node.js rising in usage, coupled with the likes of AngularJS, React and Backbone.js, JavaScript surely is a popular entity on the web and as such, its rising importance in the world of WordPress development is a welcome note.
What About PHP?
WordPress is coded in PHP, so it is pretty obvious that the role of PHP cannot be diminished. However, with the rising influence of JavaScript, how will PHP keep up? Well, PHP powers 80% of the web, so in all likelihood, there is hardly much that can be affected. But all said and done, REST API will actually influence PHP in an ostensible manner: now, for your third-party app to interact with WordPress, the app does not need to be in PHP anymore, as REST API can allow for cross-platform interaction between applications, which brings us to our next point.Cross-Platform Interaction
REST API is more of an architectural style rather than a systems protocol. As such, it can be implemented on any platform that has been built or coded via any script or language. Thus, REST API can be used by an application that is built using Ruby on Rails, or by a plugin coded in PHP, or by software written in C#. What this means is that even those applications and platforms can interact with and share data with WordPress that are otherwise not built using WordPress, or even PHP for that matter. So we can have websites and applications that are running in Python sharing data with WordPress sites, and vice versa.