The thing I don't get about node.js is that it used to have a promise abstraction and they dropped it to go callback-only. I guess the abstraction leaked, in a language not built around it?

I like to imagine Node's success comes from bringing some of E's insights to a community just ready to use them, and if the cost is manual CPS, apparently it's not too high. (Relevant E theory at http://erights.org/elib/concurrency/overview.html )