title: Selenium WebDriver: How to install the firefox extension "Firefox WebDriver"?
body: <p>I set up a browser automation project using Selenium WebDriver. It works just fine. When I try to run it on an other machine, though, it opens the browser (Firefox), but that's it, no automation. When timed out, it throws an error: <code>"Failed to start up socket within 45000 ms. Attempted to connect to the following addresses: 127.0.0.1:7055"</code>. 7055 is the default port the firefox driver attempts to use for communication (see <a href="https://code.google.com/p/selenium/wiki/FirefoxDriverInternals" rel="nofollow noreferrer" title="this">this article</a>).</p>
  
  <p>On my machine, where everything works, Firefox has an extension installed called "Firefox WebDriver 2.42.0". When I type 127.0.0.1:7055 into the browser, it opens a page titled "httpd.js". I suppose it is served by the extension, because on the other machine it's not opening.</p>
  
  <p>I was unable to find the extension in the web for download, and I was unable to understand where it comes from - it apears to not be installed manually. </p>
  
  <p>Please help.</p>
  
  <p>edit: reworded the question</p>