Capuchin

A JavaScript implementation, running on the Rubinius VM.

Usage

Given eg/nest.js:

function a(n) {
  n = n + 4;
  function b(n) {
     n = n + 5;
     return n * 2;
  }
  return n + b(7);
}

print(a(3));

Run:

bin/capuchin eg/nest.js

And you'll see:

(Loads of debug information that I haven't turned off yet, and...)
31

(Which isn't very exciting, but is correct, and demonstrates that the inner n parameter correctly shadows the outer.)

Alternatively, run something more interesting, and then fix whatever breaks.