On Google Gears, I’m definitely in the skeptical What is this “being at work while offline” of which you speak? camp. I wasn’t convinced when Adam Bosworth was singing this song five years ago and I’m still not. Doesn’t mean having programmable persistence in the browser isn’t a good idea, though. Browsers already cache heavily, of course, but not in a way that’s sensitive to the needs of any particular Ajax code. I mean, consider a mapping app; if the computer knows where I am, why shouldn’t the browser pre-populate the cache with a few hundred local map tiles? They don’t change that much. And so on. Gears at least seems pretty lockin-free.