Note: Electron was previously named Atom Shell.
Like NW.js, Electron provides a platform to write desktop applications with JavaScript and HTML and has Node integration to grant access to the low level system from web pages.
But there are also fundamental differences between the two projects that make Electron a completely separate product from NW.js:
1. Entry of Application
In NW.js the main entry point of an application is a web page. You specify a main page URL in the package.json and it is opened in a browser window as the application’s main window.
In Electron, the entry point is a JavaScript script. Instead of providing a URL directly, you manually create a browser window and load an HTML file using the API. You also need to listen to window events to decide when to quit the application.
Electron works more like the Node.js runtime. Electron’s APIs are lower level so you can use it for browser testing in place of PhantomJS.
2. Build System
In order to avoid the complexity of building all of Chromium, Electron uses libchromiumcontent to access Chromium’s Content API. libchromiumcontent is a single shared library that includes the Chromium Content module and all of its dependencies. Users don’t need a powerful machine to build Electron.
3. Node Integration
In NW.js, the Node integration in web pages requires patching Chromium to work, while in Electron we chose a different way to integrate the libuv loop with each platform’s message loop to avoid hacking Chromium. See the node_bindings code for how that was done.
4. Multi-context
If you are an experienced NW.js user, you should be familiar with the concept of Node context and web context. These concepts were invented because of how NW.js was implemented.
By using the multi-context feature of Node, Electron doesn’t introduce a new JavaScript context in web pages.
Note: NW.js has optionally supported multi-context since 0.13.