title: How do I use the HTMLUnit driver with Selenium from Python?
body: <p>How do I tell Selenium to use HTMLUnit?</p>
  
  <p>I'm running selenium-server-standalone-2.0b1.jar as a Selenium server in the background, and the latest Python bindings installed with "pip install -U selenium".</p>
  
  <p>Everything works fine with Firefox. But I'd like to use HTMLUnit, as it is lighter weight and doesn't need X. This is my attempt to do so:</p>
  
  <pre><code>&gt;&gt;&gt; import selenium
  &gt;&gt;&gt; s = selenium.selenium("localhost", 4444, "*htmlunit", "http://localhost/")
  &gt;&gt;&gt; s.start()
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
    File "/usr/local/lib/python2.6/dist-packages/selenium/selenium/selenium.py", line 189, in start
      result = self.get_string("getNewBrowserSession", start_args)
    File "/usr/local/lib/python2.6/dist-packages/selenium/selenium/selenium.py", line 223, in get_string
      result = self.do_command(verb, args)
    File "/usr/local/lib/python2.6/dist-packages/selenium/selenium/selenium.py", line 217, in do_command
      raise Exception, data
  Exception: Failed to start new browser session: Browser not supported: *htmlunit
  
  Supported browsers include:
    *firefox
    *mock
    *firefoxproxy
    *pifirefox
    *chrome
    *iexploreproxy
    *iexplore
    *firefox3
    *safariproxy
    *googlechrome
    *konqueror
    *firefox2
    *safari
    *piiexplore
    *firefoxchrome
    *opera
    *iehta
    *custom
  </code></pre>
  
  <p>So the question is, what is the HTMLUnit driver called? How do I enable it?</p>
  
  <p>The code for HTMLUnit seems to be in the source for Selenium 2, so I expected it to be available by default like the other browsers. I can't find any instructions on how to enable it.</p>