The whole point is to enable the browser to be a full proper app platform- that includes enabling web apps to work OFFLINE. The behaviour of a browser without a

The whole point is to enable the browser to be a full proper app platform- that includes enabling web apps to work OFFLINE. The behaviour of a browser without app cache is to fail to display content even if it is cached if your connection happens to be offline. the html5 app cache addresses that- and is the "standardised" alternative to google gears' local "offline" web server.