ReactJS is a JavaScript library for building elegant, performant interfaces for web applications.
Being component based React allows Blaze UI developers to build encapsulated components that manage their own state. Being written in JavaScript, rather than traditional templates, Blaze developers can easily pass rich data through to the Blaze administrative UI components, or to the front-end application components, that can be built using Blaze.
Server-side rendering in Blaze front-end applications gives stellar performance, with no loss of SEO or degradation of user experience.
React is a Facebook backed project and as such enjoys great support as a project.
License: Open Source (MIT)