Mibbit supports WebSocket, some initial numbers.
axod.blogspot.com
axod.blogspot.com
Browser usage on Mibbit main client (Snapshot):
FX3: 65%
Chrome: 12%
IE8: 7%
IE7: 6%
Opera: 3%
IE6: 3%
Safari: 3%
FX2: 1%
Chrome has really grown at an astounding rate in the webapp usage world at any rate.Among my friends, that's step 1 when you get roped into doing family tech support anymore: remove the IE shortcuts, install Chrome. Only sometimes changing the chrome shortcut to the IE icon...
I have been playing with web workers (http://github.com/revis/Really-Cloudy) and one thing that worried me was the number of people with capable browsers. From your data it looks like that isn't a problem for technical audiences.
Atleast some webapp makers and users don't care about IE.
The comet connection requires 2 keep-alive HTTP connections to make a full-duplex connection. So obviously a single socket connection doubles the number of users a single box can handle - does it actually scale that way?? Don't know.
Also, obviously, the smaller your send/receive, the better the improvement that your websocket code would see over XHR. I can imagine an application of websockets where you open multiple sockets and send a number of constantly updating data-streams from the server.
A lot of articles seem to imply that websockets is simply XHR 2.0, and I'm sure it will be used as such for a while.
But it seems to me that there are certain things that you can do with this that simply cannot be done efficiently with other technology.
(Imagine being able to smoothly track a mouse cursor or watch another person edit a document in real time, how would you do that with XHR?).
Works fine on Etherpad.
Having said that, I agree, the lag with WebSocket is likely to be a less. Hopefully WebSocket will get the ability to do deflate/gzip soon as well. That would make it a very clear winner.
On etherpad there is a lag and updates get chunked.
With websockets you could do it by the keystroke with little to no overhead.
What I'd really like to see is the breakdown of the number of packets sent as opposed to the number of bytes. I doubt the difference would be as significant.
Did you write your own http server/library or are you using an existing one for the current Comet implementation?
I really hope someday to open source it sometime. If only to show people that development in Java doesn't have to be horrible.
For extra credit, you could probably write a WebSocket implementation IN Flash using these techniques. Anyone on it?