Can you export multiple classes from a single Nodejs Module?

You can also do this in a shorter form, using destructuring assignments (which are supported natively starting from Node.js v6.0.0):

// people.js

class Jack {
  // ...
}

class John {
  // ...
}

module.exports = { Jack, John }

Importing:

// index.js

const { Jack, John } = require('./people.js');

Or even like this if you want aliased require assignments:

// index.js

const {
  Jack: personJack, John: personJohn,
} = require('./people.js');

In the latter case personJack and personJohn will reference your classes.

A word of warning:

Destructuring could be dangerous in sense that it's prone to producing unexpected errors. It's relatively easy to forget curly brackets on export or to accidentally include them on require.

---

Node.js 12 update:

Lately ECMAScript Modules received an extended support in Node.js 12.*, introducing the convenient usage of import statement to accomplish the same task (currently Node should be started with a flag --experimental-modules in order to make them available).

// people.mjs

export class Jack {
  // ...
}

export class John {
  // ...
}

Notice that files that adhere to modules convention should have an .mjs extension.

// index.mjs

import {
  Jack as personJack, John as personJohn,
} from './people.mjs';

This is much better in a sense of robustness and stability, as an attempt to import non-existing export from the module will throw an exception similar to:

SyntaxError: The requested module 'x' does not provide an export named 'y'

You can export multiple classes like this:

e.g. People.js

class Jack{
   //Member variables, functions, etc
}

class John{
   //Member variables, functions, etc
}

module.exports = {
  Jack : Jack,
  John : John
}

And access these classes as you have correctly mentioned:

var People = require('./People.js');
var JackInstance = new People.Jack();
var JohnInstance = new People.John();