# React TodoMVC Example > React is a JavaScript library for creating user interfaces. Its core principles are declarative code, efficiency, and flexibility. Simply specify what your component looks like and React will keep it up-to-date when the underlying data changes. > _[React - facebook.github.io/react](http://facebook.github.io/react)_ ## Learning React The [React getting started documentation](http://facebook.github.io/react/docs/getting-started.html) is a great way to get started. Here are some links you may find helpful: * [Documentation](http://facebook.github.io/react/docs/getting-started.html) * [API Reference](http://facebook.github.io/react/docs/reference.html) * [Blog](http://facebook.github.io/react/blog/) * [React on GitHub](https://github.com/facebook/react) * [Support](http://facebook.github.io/react/support.html) Articles and guides from the community: * [Philosophy](http://www.quora.com/Pete-Hunt/Posts/React-Under-the-Hood) * [How is Facebook's React JavaScript library](http://www.quora.com/React-JS-Library/How-is-Facebooks-React-JavaScript-library) * [React: Under the hood](http://www.quora.com/Pete-Hunt/Posts/React-Under-the-Hood) Get help from other React users: * [React on StackOverflow](http://stackoverflow.com/questions/tagged/reactjs) * [Mailing list on Google Groups](https://groups.google.com/forum/#!forum/reactjs) * _If you have other helpful links to share, or find any of the links above no longer work, please [let us know](https://github.com/tastejs/todomvc/issues)._ ## Running The app is built with [JSX](http://facebook.github.io/react/docs/jsx-in-depth.html) and compiled at runtime for a lighter and more fun code reading experience. As stated in the link, JSX is not mandatory. To run the app, spin up an HTTP server (e.g. `python -m SimpleHTTPServer`) and visit http://localhost/.../myexample/.