Firefox Developer Edition includes all the tools experienced web developers are familiar with:

• WebIDE
  Develop, deploy and debug Firefox OS apps directly in your browser, or on a Firefox OS device, with this tool that replaces App Manager.
• Responsive Design View
  See how your Website or Web app will look on different screen sizes without changing the size of your browser window.
• Valence
  Develop and debug your apps across multiple browsers and devices with this powerful extension that comes pre-installed with Firefox Developer Edition.
• Web Audio Editor
  Inspect and interact with Web Audio API in real time to ensure that all audio nodes are connected in the way you expect.
• Page Inspector
  Examine the HTML and CSS of any Web page and easily modify the structure and layout of a page.
• Web Console
  See logged information associated with a Web page and use Web Console to interact with Web pages using JavaScript.
• JavaScript Debugger
  Step through JavaScript code and examine or modify its state to help track down bugs.
• Network Monitor
  See all the network requests your browser makes, how long each request takes and details of each request.
• Style Editor
  View and edit CSS styles associated with a Web page, create new ones and apply existing CSS stylesheets to any page.

Download: mozilla.org/en-US/firefox/developer

If you like this information, give us a "Like!" on Facebook.

Source: mozilla.org