Web apps have grown in complexity in recent years. Angular, Backbone and Ember are fully fledged Javascript frameworks that bring a lot of power to the browser. jQuery really simplifies the way we manipulate elements on the page. But what if your app can be in any of hundreds of different states? How do you transition between each and every possible state of your app? We're quickly being overwhelmed by the complexity of our web apps. In this talk, you'll learn why we needed a new tool and how we determined that React, the Javascript library from Facebook, is a good fit for certain problems. Josh describes the basics of the library and how you can build quite complex apps from very simple components.