angular-cn/modules/angular2/docs/bundles/overview.md

TL;DR;

• If you write ES5 use one of the UMD bundles.
• If you experiment with Angular2 using online prototyping tools like plnkr or similar use System.register bundles with SystemJS loader.
• If you use build tools like Browserify or WebPack - bundle Angular2 as part of your build.
• For all the above cases you must use angular2-polyfills.js in a script tag to easily include polyfills and external dependencies.

Modules, barrels and bundles

Angular2 source code is authored using the ES2015 standardized module format where one module corresponds to exactly one file. Multiple modules (files) can be logically grouped into so-called "barrels". A bundle is a file the contains all the code for one or more barrels.

Most bundles come in several flavors:

• regular and minified (got .min in their name);
• regular and "development" (have .dev in their name) - "development" bundles contain in-line source maps and don't have minified flavor (minification removes in-lined source maps).

Bundles, their content and usage scenarios

Angular 2 distributes several types of bundles targeted at specific usages:

• users writing ES5 code without any transpilation steps
• users experimenting with Angular 2 and TypeScript/ES2015 using online tools like plunker, jsbin or similar

Since each identified scenario has slightly different requirements and constraints there are specific bundles for each use-case.

ES5 and ngUpgrade users

ES5 users and AngularJS 1.x users interested in the ngUpgrade path can take advantage of the bundles in the UMD format. Those are coarse-grained bundles that combine many barrels in one final file.

filename	list of barrels	dev/prod	minified?
angular2.umd.js	RxJS, angular2/core, angular2/common, angular2/compiler, angular2/platform/browser, angular2/platform/common_dom, angular2/http, angular2/router, angular2/instrumentation, angular2/upgrade	prod	no
angular2.umd.min.js	RxJS, angular2/core, angular2/common, angular2/compiler, angular2/platform/browser, angular2/platform/common_dom, angular2/http, angular2/router, angular2/instrumentation, angular2/upgrade	prod	yes
angular2.umd.dev.js	RxJS, angular2/core, angular2/common, angular2/compiler, angular2/platform/browser, angular2/platform/common_dom, angular2/http, angular2/router, angular2/instrumentation, angular2/upgrade	dev	no
angular2-testing.umd.dev.js	RxJS, angular2/core, angular2/common, angular2/compiler, angular2/platform/browser, angular2/platform/common_dom, angular2/http, angular2/router, angular2/instrumentation, angular2/upgrade, angular2/testing, angular2/http/testing, angular2/router/testing	dev	no

Warning: bundles in the UMD format are not "additive". A single application should use only one bundle from the above list.

SystemJS loader users

SystemJS loader with on-the-fly (in a browser) transpilations support is very useful for quick experiments using tools like plunker, jsbin or similar. For this scenario Angular 2 is distributed with bundles in the System.register format:

filename	list of barrels	dev/prod	minified?
angular2.js	RxJS, angular2/core, angular2/common, angular2/compiler, angular2/platform/browser, angular2/platform/common_dom, angular2/instrumentation	prod	no
angular2.min.js	RxJS, angular2/core, angular2/common, angular2/compiler, angular2/platform/browser, angular2/platform/common_dom, angular2/instrumentation	prod	yes
angular2.dev.js	RxJS, angular2/core, angular2/common, angular2/compiler, angular2/platform/browser, angular2/platform/common_dom, angular2/instrumentation	dev	no
http.js	angular2/http	prod	no
http.min.js	angular2/http	prod	yes
http.dev.js	angular2/http	dev	no
router.js	angular2/router	prod	no
router.min.js	angular2/router	prod	yes
router.dev.js	angular2/router	dev	no
upgrade.js	angular2/upgrade	prod	no
upgrade.min.js	angular2/upgrade	prod	yes
upgrade.dev.js	angular2/upgrade	dev	no
testing.dev.js	angular2/testing, angular2/http/testing, angular2/router/testing	dev	no

Note: bundles in the System.register format are "additive" - it is quite common to include several bundles in one application. For example people using Angular 2 with http and router would include: angular2.js, http.js and router.js.

Browserify / JSPM / Rollup / WebPack users

Angular 2 doesn't provide any bundles for use with packaging tools Browserify or WebPack. Those tools are sophisticated enough to build optimal bundles for production use from individual Angular 2 files distributed in the npm package. An example of an Angular 2 project built with WebPack can be found in the angular2-seed repository.

Polyfills and external dependencies

Polyfills are required for Angular 2 to function properly (the exact list depends on the browser used) and external dependencies (zone.js). To ease setup of Angular 2 applications there is one file - angular2-polyfills.js - that combines:

• a pollyfill mandatory for all browsers: reflect-metadata
• zone.js

Note: angular2-polyfills.js contains code that should be loaded into the browser as the very first code of the web application even before the module loader. The preferred solution is to load the mentioned file in a script tag as early as possible.

Users of pre-ES6 browsers might need to add an ES6 shim (e.g. es6-shim)