Yes, listening to the same music simultaneously. The users control what music plays in the rooms, as opposed to simply a shared stream. And there are public rooms in addition to private ones.
Think turntable.fm/plug.dj for the closest analogy.
Fair enough. Maybe CoffeeScript specifically isn't the answer. But the general idea of compiling neater languages into JavaScript strikes me as a better long-term solution than settling for its current syntactical warts, which are entirely historical accidents.
Controversies like the "trailing comma" strike me as evidence that JavaScript has superfluous syntax. The reason it even uses commas the way it does is that it started life as a lisp with (manager-mandated) Java-like syntax.
I happen to agree with the position that syntax that can be made implicit should be. CoffeeScript has done a good job of this. LiveScript has done an even better one. What are the arguments against using a syntactically cleaner language that compiles down to the exact same features?
Think turntable.fm/plug.dj for the closest analogy.