Strange JavaScript syntax in NodeJS examples

I've seen some NodeJS code examples on a couple of tech-blog sites with strange syntax. Have I been living under a rock or is this just the Syntax Highlighter playing silly buggers?

Example:

module.exports = (app) ->
  app.get '/', (req, res) ->
    res.send('hello world')

I presume the fact that this is an Express app is academic. Be gentle with your answers...

That’s not JavaScript; that’s CoffeeScript! You’re not missing anything… in every sense.

(CoffeeScript’s npm package lets you run CoffeeScript under Node using coffee.)

The example code you have posted is CoffeeScript, a Ruby/Python-like language that compiles directly to JavaScript. Here is an equivalent in JavaScript:

module.exports = function (app) {
    app.get('/', function (req, res) {
        res.send('hello world');
    });
};