# Workspace npm dependencies The Angular Framework, Angular CLI, and components used by Angular applications are packaged as [npm packages](https://docs.npmjs.com/getting-started/what-is-npm "What is npm?") and distributed via the [npm registry](https://docs.npmjs.com/). You can download and install these npm packages by using the [npm CLI client](https://docs.npmjs.com/cli/install), which is installed with and runs as a [Node.js®](https://nodejs.org "Nodejs.org") application. By default, the Angular CLI uses the npm client. Alternatively, you can use the [yarn client](https://yarnpkg.com/) for downloading and installing npm packages.
See [Local Environment Setup](guide/setup-local "Setting up for Local Development") for information about the required versions and installation of `Node.js` and `npm`. If you already have projects running on your machine that use other versions of Node.js and npm, consider using [nvm](https://github.com/creationix/nvm) to manage the multiple versions of Node.js and npm.
## `package.json` Both `npm` and `yarn` install the packages that are identified in a [`package.json`](https://docs.npmjs.com/files/package.json) file. The CLI command `ng new` creates a `package.json` file when it creates the new workspace. This `package.json` is used by all projects in the workspace, including the initial app project that is created by the CLI when it creates the workspace. Initially, this `package.json` includes _a starter set of packages_, some of which are required by Angular and others that support common application scenarios. You add packages to `package.json` as your application evolves. You may even remove some. The `package.json` is organized into two groups of packages: * [Dependencies](guide/npm-packages#dependencies) are essential to *running* applications. * [DevDependencies](guide/npm-packages#dev-dependencies) are only necessary to *develop* applications.
**Library developers:** By default, the CLI command [`ng generate library`](cli/generate) creates a `package.json` for the new library. That `package.json` is used when publishing the library to npm. For more information, see the CLI wiki page [Library Support](https://github.com/angular/angular-cli/wiki/stories-create-library).
{@a dependencies} ## Dependencies The packages listed in the `dependencies` section of `package.json` are essential to *running* applications. The `dependencies` section of `package.json` contains: * [**Angular packages**](#angular-packages): Angular core and optional modules; their package names begin `@angular/`. * [**Support packages**](#support-packages): 3rd party libraries that must be present for Angular apps to run. * [**Polyfill packages**](#polyfills): Polyfills plug gaps in a browser's JavaScript implementation. To add a new dependency, use the [`ng add`](cli/add) command. {@a angular-packages} ### Angular packages The following Angular packages are included as dependencies in the default `package.json` file for a new Angular workspace. For a complete list of Angular packages, see the [API reference](http://angular.io/api?type=package). Package name | Description ---------------------------------------- | -------------------------------------------------- [**@angular/animations**](api/animations) | Angular's animations library makes it easy to define and apply animation effects such as page and list transitions. For more information, see the [Animations guide](guide/animations). [**@angular/common**](api/common) | The commonly-needed services, pipes, and directives provided by the Angular team. The [`HttpClientModule`](api/common/http/HttpClientModule) is also here, in the [`@angular/common/http`](api/common/http) subfolder. For more information, see the [HttpClient guide](guide/http). **@angular/compiler** | Angular's template compiler. It understands templates and can convert them to code that makes the application run and render. Typically you don’t interact with the compiler directly; rather, you use it indirectly via `platform-browser-dynamic` when JIT compiling in the browser. For more information, see the [Ahead-of-time Compilation guide](guide/aot-compiler). [**@angular/core**](api/core) | Critical runtime parts of the framework that are needed by every application. Includes all metadata decorators, `Component`, `Directive`, dependency injection, and the component lifecycle hooks. [**@angular/forms**](api/forms) | Support for both [template-driven](guide/forms) and [reactive forms](guide/reactive-forms). For information about choosing the best forms approach for your app, see [Introduction to forms](guide/forms-overview). [**@angular/
platform‑browser**](api/platform-browser) | Everything DOM and browser related, especially the pieces that help render into the DOM. This package also includes the `bootstrapModuleFactory()` method for bootstrapping applications for production builds that pre-compile with [AOT](guide/aot-compiler). [**@angular/
platform‑browser‑dynamic**](api/platform-browser-dynamic) | Includes [providers](api/core/Provider) and methods to compile and run the app on the client using the [JIT compiler](guide/aot-compiler). [**@angular/router**](api/router) | The router module navigates among your app pages when the browser URL changes. For more information, see [Routing and Navigation](guide/router). {@a support-packages} ### Support packages The following support packages are included as dependencies in the default `package.json` file for a new Angular workspace. Package name | Description ---------------------------------------- | -------------------------------------------------- [**rxjs**](https://github.com/ReactiveX/rxjs) | Many Angular APIs return [_observables_](guide/glossary#observable). RxJS is an implementation of the proposed [Observables specification](https://github.com/tc39/proposal-observable) currently before the [TC39](https://www.ecma-international.org/memento/tc39-m.htm) committee, which determines standards for the JavaScript language. [**zone.js**](https://github.com/angular/zone.js) | Angular relies on zone.js to run Angular's change detection processes when native JavaScript operations raise events. Zone.js is an implementation of a [specification](https://gist.github.com/mhevery/63fdcdf7c65886051d55) currently before the [TC39](http://www.ecma-international.org/memento/TC39.htm) committee that determines standards for the JavaScript language. {@a polyfills} ### Polyfill packages Many browsers lack native support for some features in the latest HTML standards, features that Angular requires. [_Polyfills_](https://en.wikipedia.org/wiki/Polyfill_(programming)) can emulate the missing features. The [Browser Support](guide/browser-support) guide explains which browsers need polyfills and how you can add them. The `package.json` for a new Angular workspace installs the [core-js](https://github.com/zloirock/core-js) package, which polyfills missing features for several popular browser. {@a dev-dependencies} ## DevDependencies The packages listed in the `devDependencies` section of `package.json` help you develop the application on your local machine. You don't deploy them with the production application. To add a new `devDependency`, use either one of the following commands: npm install --dev <package-name> yarn add --dev <package-name> The following `devDependencies` are provided in the default `package.json` file for a new Angular workspace. Package name | Description ---------------------------------------- | ----------------------------------- [**@angular‑devkit/
build‑angular**](https://github.com/angular/angular-cli/) | The Angular build tools. [**@angular/cli**](https://github.com/angular/angular-cli/) | The Angular CLI tools. **@angular/
compiler‑cli** | The Angular compiler, which is invoked by the Angular CLI's `ng build` and `ng serve` commands. **@angular/
language‑service** | The [Angular language service](guide/language-service) analyzes component templates and provides type and error information that TypeScript-aware editors can use to improve the developer's experience. For example, see the [Angular language service extension for VS Code](https://marketplace.visualstudio.com/items?itemName=Angular.ng-template). **@types/... ** | TypeScript definition files for 3rd party libraries such as Jasmine and Node.js. [**codelyzer**](https://www.npmjs.com/package/codelyzer) | A linter for Angular apps whose rules conform to the Angular [style guide](guide/styleguide). **jasmine/... ** | Packages to support the [Jasmine](https://jasmine.github.io/) test library. **karma/... ** | Packages to support the [karma](https://www.npmjs.com/package/karma) test runner. [**protractor**](https://www.npmjs.com/package/protractor) | An end-to-end (e2e) framework for Angular apps. Built on top of [WebDriverJS](https://github.com/SeleniumHQ/selenium/wiki/WebDriverJs). [**ts-node**](https://www.npmjs.com/package/ts-node) | TypeScript execution environment and REPL for Node.js. [**tslint**](https://www.npmjs.com/package/tslint) | A static analysis tool that checks TypeScript code for readability, maintainability, and functionality errors. [**typescript**](https://www.npmjs.com/package/typescript) | The TypeScript language server, including the *tsc* TypeScript compiler. ## Related information For information about how the Angular CLI handles packages see the following guides: * [Building and serving](guide/build) describes how packages come together to create a development build. * [Deployment](guide/deployment) describes how packages come together to create a production build.