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 using 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.
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.
This `package.json` is used by all projects in the workspace, including the initial application 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.
**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.
[**@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 using `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 application on the client using the [JIT compiler](guide/aot-compiler).
[**@angular/router**](api/router) | The router module navigates among your application 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.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](https://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.
