Mozilla has officially released version 12 of Firefox, which improves several developer tools and introduces a new silent updater for Windows users. With the frequency of updates for Firefox—version 11 was just released about a month ago—silent automatic updates would reduce the annoying notifications and restarts that have frustrated users.
Starting with Firefox 12, you will no longer need to approve the update, wait for it to install, and then restart your browser. The process has now been moved completely to the background. Previously, the update also downloaded in the background, but installation happened on start-up, which meant users experienced delays in starting up Firefox.
Now, the update downloads and installs in the background while Firefox is still running. It will still require a restart to take effect, but it will happen so quickly that users won’t even notice it. The update also brings improvements to new built-in dev tools such as Web Console, Scratchpad, Style Editor, Page Inspector, Style Inspector, and 3D Page Inspector.
Source: SlashGear