Node.js is a platform for writing high-performance, scalable web applications and network programs in JavaScript. It has an asynchronous, non-blocking, programming model for lightning-fast speeds and enables the use of JavaScript on the server-side so that both client and server run using the same language. Until recently, highly concurrent programs were limited to hardcore network programmers but now any web developer with JavaScript skills can write the same kinds of highly-scalable programs quickly and easily.