example.js

require: "./increment";
var a = 1;
increment(a); // 2

increment.js

require: "./math";
exports: function increment(val) {
    return add(val, 1);
};

math.js

exports: function add() {
    var sum = 0, i = 0, args = arguments, l = args.length;
    while (i < l) {
        sum += args[i++];
    }
    return sum;
};

js/output.js

/******/ (function(modules) { // webpackBootstrap
/******/ 	// The module cache
/******/ 	var installedModules = {};
/******/ 	
/******/ 	// The require function
/******/ 	function require(moduleId) {
/******/ 		// Check if module is in cache
/******/ 		if(installedModules[moduleId])
/******/ 			return installedModules[moduleId].exports;
/******/ 		
/******/ 		// Create a new module (and put it into the cache)
/******/ 		var module = installedModules[moduleId] = {
/******/ 			exports: {},
/******/ 			id: moduleId,
/******/ 			loaded: false
/******/ 		};
/******/ 		
/******/ 		// Execute the module function
/******/ 		modules[moduleId].call(null, module, module.exports, require);
/******/ 		
/******/ 		// Flag the module as loaded
/******/ 		module.loaded = true;
/******/ 		
/******/ 		// Return the exports of the module
/******/ 		return module.exports;
/******/ 	}
/******/ 	
/******/ 	// The bundle contains no chunks. A empty chunk loading function.
/******/ 	require.e = function requireEnsure(_, callback) {
/******/ 		callback.call(null, require);
/******/ 	};
/******/ 	
/******/ 	// expose the modules object (__webpack_modules__)
/******/ 	require.modules = modules;
/******/ 	
/******/ 	// expose the module cache
/******/ 	require.cache = installedModules;
/******/ 	
/******/ 	
/******/ 	// Load entry module and return exports
/******/ 	return require(0);
/******/ })
/************************************************************************/
/******/ ({
/******/ // __webpack_public_path__
/******/ c: "",

/***/ 0:
/*!********************!*\
  !*** ./example.js ***!
  \********************/
/***/ function(module, exports, require) {

	var __WEBPACK_LABELED_MODULE__1 = require(/*! ./increment */ 1), increment = __WEBPACK_LABELED_MODULE__1.increment;
	var a = 1;
	increment(a); // 2

/***/ },

/***/ 1:
/*!**********************!*\
  !*** ./increment.js ***!
  \**********************/
/***/ function(module, exports, require) {

	var __WEBPACK_LABELED_MODULE__2 = require(/*! ./math */ 2), add = __WEBPACK_LABELED_MODULE__2.add;
	exports: exports["increment"] = function increment(val) {
	    return add(val, 1);
	};

/***/ },

/***/ 2:
/*!*****************!*\
  !*** ./math.js ***!
  \*****************/
/***/ function(module, exports, require) {

	exports: exports["add"] = function add() {
	    var sum = 0, i = 0, args = arguments, l = args.length;
	    while (i < l) {
	        sum += args[i++];
	    }
	    return sum;
	};

/***/ }
/******/ })

The remaining labels are removed while minimizing.

Info

Uncompressed

Hash: 76e286b599e5c0a0757814519c4540d3
Version: webpack 0.10.0-beta6
Time: 39ms
    Asset  Size  Chunks             Chunk Names
output.js  2479       0  [emitted]  main       
chunk    {0} output.js (main) 288 [rendered]
    [0] ./example.js 53 [built] {0}
    [1] ./increment.js 80 [built] {0}
        labeled require ./increment [0] ./example.js 1:0-23
    [2] ./math.js 155 [built] {0}
        labeled require ./math [1] ./increment.js 1:0-18

Minimized (uglify-js, no zip)

Hash: 76e286b599e5c0a0757814519c4540d3
Version: webpack 0.10.0-beta6
Time: 82ms
    Asset  Size  Chunks             Chunk Names
output.js   468       0  [emitted]  main       
chunk    {0} output.js (main) 288 [rendered]
    [0] ./example.js 53 [built] {0}
    [1] ./increment.js 80 [built] {0}
        labeled require ./increment [0] ./example.js 1:0-23
    [2] ./math.js 155 [built] {0}
        labeled require ./math [1] ./increment.js 1:0-18