MacRumors was digging through the latest developer beta of Mac OS X Lion when it found a rather intriguing new option — if you choose “Restart to Safari” on the user lock screen, the computer will reboot into a mode which consists entirely of the web browser. If that sounds familiar, perhaps you’ve heard of Google’s Chrome OS , a partially-fledged operating system that runs within the browser itself… but we haven’t heard Apple express a desire for any such thing. Now, certainly we’ve seen a number of Windows desktops and laptops ship with a secondary, browser-centric OS like Splashtop in order to have an instant-on mode, but if you have to boot and reboot the computer to get to Safari, that doesn’t sound like much of an improvement. Perhaps it’s a way to let guests (or children) entertain themselves without giving them access to your files? All we know for certain is that it’s a most mysterious option. Mac OS X Lion beta reveals “Restart to Safari” browser-only mode originally appeared on Engadget on Sun, 12 Jun 2011 19:18:00 EDT. Please see our terms for use of feeds . Permalink