:memo: Add technical differences to node-webkit, fixes #242.

README.md

@@ -1,7 +1,5 @@
 # Atom Shell [![Build Status](https://travis-ci.org/atom/atom-shell.svg?branch=master)](https://travis-ci.org/atom/atom-shell)
 
-## Overview
-
 The Atom Shell framework lets you write cross-platform desktop applications
 using JavaScript, HTML and CSS. It is based on [node.js](http://nodejs.org) and
 [Chromium](http://www.chromium.org) and is used in the [Atom

docs/README.md

@@ -36,6 +36,8 @@ Modules for both sides:
 
 * [Coding style](development/coding-style.md)
 * [Source code directory structure](development/source-code-directory-structure.md)
+* [Technical differences to node-webkit](development/atom-shell-vs-node-webkit.md)
+
 * [Build instructions (Mac)](development/build-instructions-mac.md)
 * [Build instructions (Windows)](development/build-instructions-windows.md)
 * [Build instructions (Linux)](development/build-instructions-linux.md)

docs/development/atom-shell-vs-node-webkit.md

@@ -0,0 +1,48 @@
+# Technical differences to node-webkit
+
+Like node-webkit, atom-shell provides a platform to write desktop applications
+with JavaScript and HTML, and has node integration to grant access to low level
+system in web pages.
+
+But there are also fundamental differences between the two projects that making
+atom-shell a completely product from node-webkit:
+
+1. Entry of application
+
+In node-webkit, the main entry of an application is a web page, you specify a
+main page in the `package.json` and it would be opened in a browser window as
+the application's main window.
+
+While in atom-shell, the entry point is a JavaScript script, instead of
+providing a URL directly, you need to manually create a browser window and load
+html file in it with corresponding API. You also need to listen to window events
+to decide when to quit the application.
+
+So atom-shell works more like the node.js runtime, and APIs are more low level,
+you can also use atom-shell for web testing purpose like
+[phantomjs](http://phantomjs.org/),
+
+2. Build system
+
+In order to avoid the complexity of building the whole Chromium, atom-shell uses
+[libchromiumcontent](https://github.com/brightray/libchromiumcontent) to access
+Chromium's Content API, libchromiumcontent is a single, shared library that
+includes the Chromium Content module and all its dependencies. So users don't
+need a powerful machine to build atom-shell.
+
+3. Node integration
+
+In node-webkit, the node integration in web pages requires patching Chromium to
+work, while in atom-shell we chose a different way to integrate libuv loop to
+each platform's message loop to avoid hacking Chromium, see the
+[`node_bindings`](../../atom/common/) code for how that was done.
+
+4. Multi-context
+
+If you are an experienced node-webkit user, you should be familiar with the
+concept of node context and web context, these concepts were invented because
+of how the node-webkit was implemented.
+
+By using the [multi-context](http://strongloop.com/strongblog/whats-new-node-js-v0-12-multiple-context-execution/)
+feature of node, atom-shell doesn't introduce a new JavaScript context in web
+pages.