What does this have to do with Opera Unite? It has the word "server" in the API name. Does that mean I can link to Apache and say that they beat Opera to the idea? Opera's not saying they came up with the first local server; they're just giving the end-user the ability to serve their own content easily and without relying on the cloud.
I think implied was the fact that content serving from browser has been available through Gears (which a lot of people have installed), but it hasn't quite caught on. The difference (as I see it) is that Opera makes it REALLY easy (I can start playing with Opera right away, whereas Gears API looks scary at first sight).
Opera Unite and Gears LocalServer are completely different. (I'm using the LocalServer API for the application I'm writing at work.)
LocalServer saves a set of static files (e.g. HTML, JavaScript, CSS, images) from the web. When the browser requests those files later, they will be served from the LocalServer disk cache instead of the remote server. So the pages will load faster and can be available offline (if the pages are designed to run without accessing any other network resources). It's like a browser cache on steroids. For an example application, see the latest version of WordPress, which has an option to load the admin UI into a LocalServer cache.
LocalServer lets you serve requests from disk to browser on a single computer, while Unite lets you serve requests from one computer to another over the internet. LocalServer is useful for offline work, while Unite is useful for communicating on a network.
If you used Unite for a single-user application (where the client and server are all on one machine) then it might provide some of the functionality of Gears LocalServer. But I suspect that the use of a central proxy server in Unite would eliminate both the performance benefits and offline features for this scenario.
The localserver in Gears is to serve offline, local content to your browser for specific websites that are written to use Gears. It doesn't do anything even close to what Unite does.
