Seems to me you could have just had Jetty/OpenCV send back the coords of the faces, then have Javascript draw a box around them. Would have saved quite a bit of bandwidth and removed the need for experimental APIs.
I think you would still want WebRTC and Web Sockets to stream the webcam to Jetty/OpenCV. Yeah, he could have sent just coords back to save on bandwidth though.
Just because HTML5 != work in every HTML5 browser.
"Numbers don't mean anything anymore they say". Well for HTML5 thats pretty much spot on.. and that's unfortunate.
Normally quote marks (the " character) are used if you're quoting something, so I was wondering where you are quoting that from. To be pedantic, what I'm looking for is a citation (of the quote, not of the fact).