A user interface framework written in javascript.
It is used both for websites, and for mobile applications.
It is also referred to as react.js

Documentation

api docs/overview https://reactjs.org/docs/react-api.html

homepage https://reactjs.org/

codepen (interactive editor) https://codepen.io/pen

Basics

react environments

react anatomy

react components

api docs/overview	https://reactjs.org/docs/react-api.html
homepage	https://reactjs.org/
codepen (interactive editor)	https://codepen.io/pen