Examine source code of IE NetRenderer button

{
  "manifest_version": 2,
  "applications": {
    "gecko": {
      "id": "ienetrenderer-nico@nc"
    }
  },
  "name": "IE NetRenderer button",
  "version": "1.4resigned1",
  "author": "nico@nc",
  "description": "__MSG_extensionDesc__",
  "icons": {
    "48": "icons/nr-icon-48.png",
    "96": "icons/nr-icon-96.png"
  },
  "browser_action": {
    "browser_style": true,
    "default_popup": "popup.html",
    "default_title": "IE NetRenderer",
    "default_icon": "icons/nr-button.svg"
  },
  "permissions": [
    "activeTab"
  ],
  "default_locale": "en"
}