I usually shrug off these JS demos but this is just getting ridiculous. The amount of stuff that people are creating with JS these days is amazing. Atwood's Law indeed.
I've seen a couple of JS VNC clients that use a canvas tag for the drawing surface before now, though they used some other language from the translation layer between the browser based client and the real server (this uses node to do that job, so still uses an extra layer but isn't using two completely different languages).
I've considered writing one that would operate on broken old browsers with no canvas support (in case I'm ever stuck with just IE6/7/8 in a place where I need to remote control one of my machines) which would take some extra work to be even moderately efficient, the server half having to translate changes into images to be delivered and positioned by the client half, and the client half dropping blocks as they become irrelevant (as their entire area has been replaced by later updates).
JS as a language is perfectly complete in terms of being capable of all this. The missing parts are not in the langauge but the supporting libraries (i.e. you can't just open a TCP connection client-side).
