I'd like to see a clearer up-front description on the front page. This is clearly for people-in-the-know, so just letting me categorize this quickly would be really helpful.

I think this is something for doing server-side Javascript development, with integrated hosting and an IDE. It's not clear to me how things like persistence work; since Javascript is somewhat novel in this role these things aren't obvious. It's not like PHP, where I'd just assume MySQL.

I see you are talking about new programmers using this, but I wouldn't try to talk to both audiences at once. Either have a separate entry page for new programmers, or just skip it (realistically it's only early adopters who are going to be interested in this for the near future).