The Mozilla Foundation has released Firefox 12, which contains a number of new features, notably to the browser’s developer tools. It also introduces silent updates for Windows users, and fixes eight security issues, two of which are critical.
You can use the program’s built-in auto-updater to get the latest version of Firefox, or you can download Firefox here. Silent updates for Mac OS X versions of Firefox are planned for version 14, which shouldn’t be too far in the future, given the program’s rapid release schedule.