The title basically says it all. I’m aware this can’t be done using traditional means. I’m not aware of any way to do it using Web Sockets, though I’ve never built anything more than toy apps with them.
It is fine if the solution is browser-specific (even on the client-side; i.e. peer-to-peer communication would also be awesome). For instance, is there any way to accomplish this using Chrome’s NaCl?
Furthermore, if this isn’t possible now, is there any fleshed-out specification for how it will work in the future? For instance, Chromium-based browsers are experimenting with a “P2P Javascript API” which appears to be currently entirely undocumented.
Here’s the HTML5 spec on it:
http://www.whatwg.org/specs/web-apps/current-work/multipage/video-conferencing-and-peer-to-peer-communication.html#peer-to-peer-connections, though its status is unclear.
Sorry if this question is a bit haphazard; I’m basically interested in the current status of all in-browser APIs that could be used for p2p communication.
Edit: I’m not interested in Flash p2p. I’m aware it can be done, and is definitely a solution to current p2p problems, however I’m interested in new technology.
Update May 2012: For those still looking at this, the peerconnection API is slowly making its way into browsers. It is now experimentally in Chrome, along with the rest of the WebRTC API. You can check out the documentation and spec here.
There’s Opera Unite but I’m not aware of any cross-browser standardization effort based on that. I think by default it proxies through Opera’s servers for DNS, but you can set it up for direct connections.