Firefox Driver

Firefox driver is included in the selenium-server-stanalone.jar available in the downloads. The driver comes in the form of an xpi (firefox extension) which is added to the firefox profile when you start a new instance of FirefoxDriver.

Pros

Runs in a real browser and supports Javascript
Faster than the InternetExplorerDriver

Cons

Slower than the HtmlUnitDriver

Important System Properties

The following system properties (read using System.getProperty() and set using System.setProperty() in Java code or the "-DpropertyName=value" command line flag) are used by the FirefoxDriver:

Property	What it means
webdriver.accept.untrusted.certs	?
webdriver.assume.untrusted.issuer	?
webdriver.development	Never use in production Indicates that we're in development mode.
webdriver.enable.native.events	?
webdriver.firefox.bin	The location of the binary used to control firefox.
webdriver.firefox.port	?
webdriver.firefox.profile	The name of the profile to use when starting firefox. This defaults to webdriver creating an anonymous profile
webdriver.firefox.useExisting	Never use in production Use a running instance of firefox if one is present
webdriver.log.file	Log file to dump javascript console logging to
webdriver.firefox.logfile	Log file to dump firefox stdout/stderr to
webdriver.reap_profile	Should be "true" if temporary files and profiles should not be deleted

Normally the Firefox binary is assumed to be in the default location for your particular operating system:

OS	Expected Location of Firefox
Linux	firefox (found using "which")
Mac	/Applications/Firefox.app/Contents/MacOS/firefox
Windows	%PROGRAMFILES%\Mozilla Firefox\firefox.exe

By default, the Firefox driver creates an anonymous profile

Running with firebug

Download the firebug xpi file from mozilla and start the profile as follows:

   File file = new File("firebug-1.8.1.xpi");
   FirefoxProfile firefoxProfile = new FirefoxProfile();
   firefoxProfile.addExtension(file);
   firefoxProfile.setPreference("extensions.firebug.currentVersion", "1.8.1"); // Avoid startup screen

   WebDriver driver = new FirefoxDriver(firefoxProfile);

-Beta- load fast preference

There is beta feature to make firefox not wait for the full page to load after calling .get or .click. This may cause immediate find's to break, so please be sure to use an implicit or explicit wait too. This is only available for Firefox and not other browsers.

   FirefoxProfile fp = new FirefoxProfile();
   fp.setPreference("webdriver.load.strategy", "unstable"); // As of 2.19. from 2.9 - 2.18 use 'fast'
   WebDriver driver = new FirefoxDriver(fp);