I am using Ubuntu 11.04 and selenium 2.9.0 Here is how it is configured in my root pom:
org.seleniumhq.selenium
As long as I know that the java command
WebDriver driver = new FirefoxDriver();
will run the installed Firefox browser on your computer.
but reading the JavaDoc at http://selenium.googlecode.com/svn/trunk/docs/api/java/index.html I realised that there can be way how to override it:
FirefoxBinary binary = new FirefoxBinary(new File("path/to/binary"));
FirefoxProfile profile = new FirefoxProfile();
WebDriver driver = new FirefoxDriver(binary, profile);