Silent, background updates, i.e. the kind you don't even notice happening, have been in Firefox for a few versions. Now, Mozilla is bringing the feature to Thunderbird, the email client it abandoned, somewhat, but which will still get active development for a while and active support for a while longer.
The feature landed
in the Daily channel, Thunderbird 17, so it's going to be a few months until it makes its way up the channels to go stable.
Still, it means that users will soon forget about having to update and just use the client while still making the most of any new features to come.
Obviously, the silent updates feature in Thunderbird will be identical to the one in Firefox. In fact they'll share the Mozilla update service that runs in the background and checks for newer versions, downloading and installing them if they exist.
Silent updates and background updates are two separate features, but they're meant to work together. Silent updates happen without any prompts, including the Windows UAC prompt. This is what the updater service is needed for.
Background updates go one step further and ensure that the new version is not only downloaded automatically, but is also installed in the background while Thunderbird, or Firefox for that matter, is running.
The new files are extracted and installed to a separate folder which then gets switched with the one containing the older version the next time Thunderbird starts. All of this happens without any user notification. Because the email client is already installed when the user restarts it, there will no delay at startup.
The two features have been pushed the Thunderbird daily builds and will be tested over the weekend. If things go well, silent updates, background updates or both may be pushed to Thunderbird 16, so they'll land six weeks faster in the stable channel.