React is an open source JavaScript library developed by Facebook since 2013. The main purpose of this library is to facilitate the creation of single-page web applications, via the creation of components that depend on a state and generate an HTML page (or portion) at each state change.
React is a library that only manages the application interface, considered as the view in the MVC model. Thus, it can be used with another library or MVC framework like AngularJS. The library stands out from its competitors by its flexibility and performance, working with a virtual DOM and updating the rendering in the browser only when necessary.
The library is used by Netflix (server-side only since October 25, 2017 to gain 50% performance4), Yahoo, Airbnb, Sony, Atlassian as well as by Facebook teams, applying dogfooding on the eponymous social network, Instagram or even WhatsApp. At the end of 2015, WordPress.com announced Gutenberg, an interface for WordPress site editors, developed in JavaScript with Node.js and React.
