Google says the new feature will see use "checking for server-side changes and pre-emptively loading content into local storage," and it's not hard to imagine how apps could use the feature. A could listen for messages, for example, and then pop up a new window should somebody want to message you. A could watch for changes made to your online docs and download them locally, ready for you to work on them instantly when you choose.

The background processes keep running for as long as Chrome is running, even if no browser windows are open. Right-clicking the taskbar icon will allow users to see what background apps are running.

One of the central definitions of a contemporary operating system is the capability to run tasks in the background. MS-DOS did it with infamous terminate-and-stay-resident programs, while . Linux and Unix use .

As with those operating systems, significant security issues come up with the capability to run background apps. Running code in the background without the user's knowledge is the modus operandi of viruses, for example.

It's not clear how Chrome is going to be able to tell apart good and bad background processes, or whether Google intends to rely on to do so.