The open-source developer has been working on silent updating for nearly two years. At one point, it thought it could add the feature to Firefox 4, which shipped in March 2011, but the company abandoned work when that version was delayed several times for other reasons. And late last year, Mozilla said it was shooting for silent updating in Firefox 10, which debuted in January 2012. Those plans were also scrapped.

Windows, Mac and Linux editions of can be downloaded manually from Mozilla's site. Users running Firefox 4 or later will be offered the upgrade through the browser's own update mechanism.

The next version of Firefox is scheduled to ship June 5.

in Computerworld's Browsers Topic Center.