Google's Gears of War

Gears is a browser extension that we hope -- with time and plenty of input and collaboration from outside of Google -- can make not just our applications but everyone's applications work offline.

Well, not exactly gears of war, not least because Google has wisely made the code freely available under an open source licence:

We are releasing Gears as an open source project and we are working with Adobe, Mozilla and Opera and other industry partners to make sure that Gears is the right solution for everyone.

But certainly likely to represent the start of a skirmish or two in the field of offline working.