React can be used to manage all the views in your web applications in a simple and easy way.
The best thing about React is that it allows you to do "No Nonsense View Engineering"
React introduces something called "Immutable Components" instead of not-so-intelligent templates and instead of substituting variables whose values have changed in a component, it re-renders the whole component again.
Though the term "Re-render" sounds expensive, React overcomes this by maintaining a Virtual DOM (also called the Shadow DOM) technique, which is an in-memory "clone" of the actual DOM. It applies its re-rendering logic on the in-memory Virtual DOM and in the end interacts with the Window Document only once.
A very detailed explanation of how the Virtual DOM diff technique is intelligent is given here.
Well, React JS does make you feel you are a bit back to the pre-AJAX '90s era when any change in a web page means a page reload. The Web was indeed simple those days!!
React JS is open source (Github Repo) as well!!
I had outlined the main features of React in a talk given at a Bangalore JS meetup.
Another really good thing about React is that it is very flexible for use alongwith with the libraries and frameworks you are already working in your current projects.