What is Node.js?

Node.js is a platform built on Chrome’s JavaScript runtime for easily building fast and scalable network applications. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.

Node.js. It’s the latest in a long line of “Are you cool enough to use me?” programming languages, APIs, and toolkits. In that sense, it lands squarely in the tradition of Rails, and Ajax, and Hadoop, and even to some degree iPhone programming and HTML5. Go to a big technical conference, and you’ll almost certainly find a few talks on Node.js, although most will fly far over the head of the common mortal programmer.

Node.js training

Dig a little deeper, and you’ll hear that Node.js (or, as it’s more briefly called by many, simply “Node”) is a server-side solution for JavaScript, and in particular, for receiving and responding to HTTP requests. If that doesn’t completely boggle your mind, by the time the conversation heats up with discussion of ports, sockets, and threads, you’ll tend to glaze over. Is this really JavaScript? In fact, why in the world would anyone want to run JavaScript outside of a browser, let alone the server?

It is an open source, cross-platform runtime environment for developing server-side and networking applications. Node.js applications are written in JavaScript, and can be run within the Node.js runtime on OS X, Microsoft Windows, and Linux.

Node.js also provides a rich library of various JavaScript modules which simplifies the development of web applications using Node.js to a great extent.

Node.js = Runtime Environment + JavaScript Library

The good news is that you’re hearing (and thinking) about the right things. Node really is concerned with network programming and server-side request/response processing. The bad news is that like Rails, Ajax, and Hadoop before it, there’s precious little clear information available. There will be, in time — as there now is for these other “cool” frameworks that have matured — but why wait for a book or a tutorial when you might be able to use Node today, and dramatically improve the maintainability of your code and even the ease with which you bring on programmers?

A warning to the Node experts out there

Node is like most technologies, that are new to the masses, but old hat to the experienced few: it’s opaque and weird to most but completely usable for a small group. The result is that if you’ve never worked with Node, you’re going to need to start with some pretty basic server-side scripts. Take your time making sure you know what’s going on, because while this is JavaScript, it’s not operating like the client-side JavaScript you’re used to. In fact, you’re going to have to twist your JavaScript brain around event loops and waiting, and even a bit of network theory.

Unfortunately, this means that if you’ve been working and playing with Node for a year or two, much of this article is going to seem pedestrian and overly simplistic. You’ll look for things like using Node on the client, or heavy theory discussions on evented I/O and reactor patterns, and npm. The reality is that while that’s all interesting — and advances Node to some pretty epic status — it’s incomprehensible to someone who is just getting started out. Given that, maybe you should pass this piece onto your co-workers who don’t know Node, and then when they’re buying into Node’s usefulness, start to bring them along with the more advanced Node use cases.