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.
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.
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.
**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).
[**@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/<br />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/<br />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).
[**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.
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.
**@angular/<br/>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).
[**codelyzer**](https://www.npmjs.com/package/codelyzer) | A linter for Angular apps whose rules conform to the Angular [style guide](guide/styleguide).
[**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).
[**tslint**](https://www.npmjs.com/package/tslint) | A static analysis tool that checks TypeScript code for readability, maintainability, and functionality errors.
