国外
在Qura上有人问过这个问题，有比较好的回答：
What are the biggest websites built with Node.js on the server side?
Walmart
E-bay / PayPal
Paypal是最早将Node.js用于生产环境的公司之一。在他们的开发者博客中记录了当初使用node.js和java分别做开发，前者体现出来的优势：
We started in January and it took us a few months to get the necessary infrastructure in place for node.js to work in PayPal, e.g. sessions, centralized logging, keystores. During this time we had five engineers working on the Java application. Two months in to the Java development, two engineers started working on the parallel node.js app. In early June they met at a crossroads, the applications had the same set of functionality; the node.js application, a smaller team with a two month delayed start, had quickly caught up. A few details stood out after we ran the test cases and both applications passed the same functional tests.
How LinkedIn used Node.js and HTML5 to build a better, faster app
那个时候，他们的web app是基于Underscore.js+Backbone.js的。