NW.js under the hood

As we stated in the introduction, NW.js, made by Roger Wang of Intel's Open Source Technology Center (Shanghai office) in 2011, is a web app runtime based on Node.js and the Chromium open source browser project. To understand how it works, we must first analyze its two components:

Since the browser, for security reasons, cannot access the application layer and since Node.js lacks a graphical interface, Roger Wang had the insight of combining the two technologies by creating NW.js.

The following is a simple diagram that shows how Node.js has been combined with WebKit in order to give NW.js applications access to both the GUI and the operating system:

In order to integrate the two systems, which, despite speaking the same language, are very different, a couple of tricks have been adopted. In the first place, since they are both event-driven (following a logic of action/reaction rather than a stream of operations), the event processing has been unified. Secondly, the Node context was injected into WebKit so that it can access it.

The amazing thing about it is that you'll be able to program all of your applications' logic in JavaScript with no concerns about where Node.js ends and WebKit begins.

Today, NW.js has reached version 0.12.0 and, although still young, is one of the most promising web app runtimes to develop desktop applications adopting web technologies.