作为用于构建用户界面的React，我们很抱歉稍微延迟了一下这次发布的版本。正如我们所说：我们一直忙于binge-watching卡片。但现在我们准备好了,闲话少说,我们这次就发布了React v15的测试版本。
主要改进：
Document.createElement is in and data-reactid is out
No more extra <span>s
Rendering null now uses comment nodes
Improved SVG support
重大改进：
Deprecated APIs removed from React, specifically findDOMNode, render, renderToString, renderToStaticMarkup, and unmountComponentAtNode.
Deprecated APIs removed from React.addons, specifically batchedUpdates and cloneWithProps.
Deprecated APIs removed from component instances, specifically setProps, replaceProps, and getDOMNode.
详情请看：https://facebook.github.io/react/blog/2016/03/07/react-v15-rc1.html