With the Objective-C bridge, you can jump into OS X app development with JavaScript
Tyler Gaw is a Freelance Web Designer & Developer in Brooklyn, New York. He writes:
OS X Yosemite introduced JavaScript for Automation. This makes it possible to access native OS X frameworks with JavaScript. I’ve been digging in to this new world and putting together examples along the way. In this post I’ll explain the basics and step through building a small example app.
Read the article at tylergaw.com