Mozilla Firefox 11.0

Installing Firefox 11 was a fine, quick experience. Keep in mind that Firefox now has four "channels," so if you've been on the beta channel since the days of version 3.6, you will stay on it until you download the installer for a different channel. There's no in-channel way to switch channels. If you're updating from version 3.6 to version 11, the process is likely to take several minutes because of the significant code changes.
Firefox uses automatic updates, although Windows users will still see the User Account Control box appear.
Careful Firefox observers will notice that the browser no longer ships with a separate icon for Safe Mode. Simply hold down Shift; when you click on the Firefox icon to open a box, you will be allowed to customize which settings carry over to Safe Mode.
Firefox automatically installs a Windows 7 Taskbar icon if you choose it as your default browser. Uninstalling the browser does not leave behind any icons or folders if you choose to remove your settings at the same time.
A new feature checks your add-ons to see which ones you installed and which ones come from third-party vendors, such as security suite makers. The browser will now ask you if you'd like to disable any of these third-party add-ons. On top of that, all future third-party add-ons will be blocked from autoinstalling. Instead, you'll be presented with the option to allow them or block them on a per-case basis. This puts Firefox squarely on the side of the user.