FHIR for JavaScript

Hi guys

I am looking for a reference implementation of FHIR spec in JavaScript to be used in a Node API server. After crawling the FHIR website, I believe this is it: http://hl7.org/fhir/downloads.html.

Is there a github project for the JavaScript code? Is it published to npm or is it distributed just in a zip file?

Cheers
Alvin