Eariler this week, Mozilla released version 30 of their popular web browser, Firefox, and now Firefox 30 is available in the official Fedora Repositories for Fedora 20 (the Fedora 19 update is still in the testing phase).
Firefox 30 is not as big of an update as the previous Firefox 29, however, two notable features implemented in this update is the addition of a new Sidebars Button, and support for GStreamer 1.0. The new sidebars button adds the option to place a button in the firefox tool bar to show (and switch between) the firefox sidebars (e.g. the bookmarks & history sidebars). Note that on Fedora this button will not appear automatically in your firefox interface after updating, you will need to customize your firefox to add the button.
To get the new version of firefox on Fedora 20, either update using the Software application in Fedora, or use the command sudo yum update firefox.