React is a JavaScript library for creating user interfaces, by Facebook (News – Alert) and Instagram. It is designed to be simple, as you express how your app should look at any given point in time and React will automatically manage all user interface (UI) updates when the underlying data changes. React is concerned with building reusable components.

In January of this year, Facebook introduced a framework that allows developers to build native mobile apps with JavaScript called React Native. The primary goal of React Native is to allow developers to bring the power of the React programming model to mobile app development. It is described as not being designed to be a cross platform, write-once run-anywhere, tool, but rather learn-once write-anywhere tool.

Earlier this month, Facebook announced that it will stop using HTML or HTML5 in favor of its React Native JavaScript framework. During a press event in London, Facebook’s director of developer infrastructure, David Mortenson told journalists that the social networking company will not be writing future mobile apps in HTML and vanilla JavaScript.

Mortenson admitted that the switch from HTML5 to React Native has been a challenge. He said, “It was a really big shift we had to make. We decided the phones were not yet powerful enough to have a really awesome, first-class experience for iOS and Android (News – Alert), so we bit the bullet.”

Enter Facebook Infer, a tool intended to detect bugs in Android and iOS apps before they ship. Mortenson said, “We haven’t had as much success open-sourcing Android projects to date, but Infer is one of the projects that we’ve released this year that has a very strong Android resonance.” It is a static analysis tool that can produce a list of potential bugs if you supply it with Objective-C, Java, or C code. Mortenson also announced that Facebook would be open-sourcing Infer.