React is a library developed and used at Facebook for building user interfaces. It can be seen as the V in MVC as it makes no assumptions about the rest of the technology stack. Using React Native it can even be used to power native apps.
In React you can write HTML directly in JS using an XML-like syntax called JSX. JSX compiles to JS and is optional, but does make the code more expressive.
Data flow in React is one-way which makes it easier to reason about and avoid mistakes. This quality can be enhanced using Flux, Facebook’s complementary application architecture, or Redux which many people see as a “better Flux”.
React Native section to be completed.