This is a platform meant for developers to practice programming in a fun way. Also coders are able to battle with other experienced coders all over the world.
At the moment only JavaScript. Fortunately, the platform is prepared for other languages and Python and Go are next (coming very soon).
No, Battle only have anonymous matches at the moment.
Not at the moment, but logged battles are planned.
The permission is required in order to present the participant country flag at the end of the match.