How to open a new tab using Selenium WebDriver?

Question

How to open a new tab in the existing Firefox browser using Selenium WebDriver (a.k.a. Selenium 2)?

Answer 1

Almost all answers here are out of date.

WebDriver now has support for opening tabs:

browser = Selenium::WebDriver.for :chrome
new_tab = browser.manage.new_window

Will open a new tab. Opening a window has actually become the non-standard case:

browser.manage.new_window(:window)

The tab or window will not automatically be focussed. To switch to it:

browser.switch_to.window new_tab