Yesterday, Joyent and Magnetk introduced a new 'product' (or is it a 'platform'?) called Slingshot. From the Joyent blog: "Joyent Slingshot allows developers to deploy Rails applications that work the same online and offline (with synchronization) and with drag into and out of the application just like a standard desktop application."
This is pretty cool. The story is: develop your Rails application like normal, add some special processing to handle sync'ing data between an off-line and on-line mode, and you can run your app in a local browser. Well, not quite a local browser. It's actually an application 'shell' which has an HTML widget as it's client area. But it can do more than your average browser; it has additional desktop-y capabilities available to it, like drag-n-drop, native file-system integration, etc.
That last bit: 'more than the average browser', is what I really like. It's actually more, and less. Watch the movie on the Joyent site. Where are the address bar, and Home, Back, and Forward buttons? Banished. As they should be. At least for 'apps'. They're great for hypertext.
I suppose there will be the eventual question about security. I'm guessing this is a fairly safe environment, since the opportunity to run someone else's code is very constrainable. Don't add links to someone else's pages in your app. Constrained, for security, but a loss of function as well. Probably a reasonable trade-off.
Can't wait to see more technical details. Dare we hope for some 'open-ness'?
Lastly, I kind of wonder how far you could take Eclipse (or even just SWT) to build something like this; use the HTML widget and see how far you can extend/integrate it into an application. If I wasn't tied up in server-y goop right now, I'd be poking around there. And what ever happened to XULRunner (last update: 10-Jun-2006)?