# Welcome to MDN data > **Note** > We are in the process of deprecating the `mdn/data` package in favor of [`w3c/webref`](https://github.com/w3c/webref). > If you depend on this project, let us know in our community [GitHub discussions](https://github.com/mdn/mdn-community/discussions/categories/platform). > Thank you. [![NPM version](https://img.shields.io/npm/v/mdn-data.svg)](https://www.npmjs.com/package/mdn-data) [![lint](https://github.com/mdn/data/actions/workflows/lint.yml/badge.svg)](https://github.com/mdn/data/actions/workflows/lint.yml) This repository contains general data for Web technologies and is maintained by the [MDN team at Mozilla](https://wiki.mozilla.org/MDN). ## Repository contents The data in this repository is used in MDN Web Docs to build [information boxes](https://developer.mozilla.org/en-US/docs/Web/CSS/background) and [sidebar navigation](https://developer.mozilla.org/en-US/docs/Web/API/Window). External tools make use of this data as well, for example, the [CSSTree](https://github.com/csstree/csstree/) CSS parser. There's a top-level directory for each broad area covered: for example, `api` and `css`. Inside each of these directories is one or more JSON files containing the data. ### api Contains data about Web APIs: - API inheritance (interface inheritance and mixin implementations) ### css Contains data about: - CSS at-rules - CSS functions - CSS properties - CSS selectors - CSS syntaxes - CSS types - CSS units For more information, see the [CSS data](./css/README.md) documentation and the [Updating CSS JSON DB](./docs/updating_css_json.md) guide. ### l10n The l10n folder contains localization strings that are used in the various json files throughout this repository. ## Problems? If you find a problem, please [file an issue](https://github.com/mdn/data/issues/new). ## Contributing We're very happy to accept contributions to this data. Please familiarize yourself with the schema for the data you're editing, and send us a pull request. See the [CONTRIBUTING.md](./CONTRIBUTING.md) document for more information. ## See also - [https://github.com/mdn/browser-compat-data](https://github.com/mdn/browser-compat-data) for compatibility data for Web technologies