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CONTRIBUTING.md

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+# Contributing
+
+Wappalyzer is an [MIT-licensed](https://github.com/aliasio/wappalyzer/blob/master/LICENSE), open source project written in JavaScript. Anyone is welcome to contribute.
+
+## Getting started
+
+To get started, see the [README](https://github.com/aliasio/wappalyzer/blob/master/README.md).
+
+## Submitting changes
+
+-   First, run `yarn run validate` to identify any issues.
+-   Use descriptive commit messages, e.g. 'Add WordPress detection'.
+-   Push your commits to a new branch on your own fork.
+-   Finally, submit a [pull request](https://help.github.com/articles/about-pull-requests/) and describe your changes.
+
+## Adding a new technology
+
+Wappalyzer uses [regular expressions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions) to fingerprint technologies. Refer to the [specification](https://github.com/AliasIO/wappalyzer/blob/master/README.md#specification) for detail.
+
+-   Add a new block to [`src/technologies.json`](https://github.com/aliasio/wappalyzer/blob/master/src/technologies.json).
+-   Add an icon to [`src/drivers/webextension/images/icons`](https://github.com/aliasio/wappalyzer/tree/master/src/drivers/webextension/images/icons). The image must be square, either SVG or PNG (32 x 32 pixels).
+
+Only widely used technologies are accepted. When creating a pull request, include ten or more links to websites that use the application, a GitHub page with at least 1,000 stars or anything that will help establish the size of the user base.
+
+## Adding a new category
+
+Please [open an issue on GitHub](https://github.com/aliasio/wappalyzer/issues) first to discuss the need for a new category.
+
+To add a category, edit [`src/technologies.json`](https://github.com/aliasio/wappalyzer/blob/master/src/technologies.json) and update every [locale](https://github.com/aliasio/wappalyzer/tree/master/src/drivers/webextension/_locales). You may use the English category name in all of them.
+
+## Adding a new translation
+
+To add a new translation, copy the `en` folder in [`src/drivers/webextension/_locales`](https://github.com/aliasio/wappalyzer/tree/master/src/drivers/webextension/_locales), rename it to the relevant two-letter country code and update the containing `messages.json` file.
+
+## Adding a new feature
+
+Please [open an issue on GitHub](https://github.com/aliasio/wappalyzer/issues) first. New features and large changes are rarely accepted without prior discussion.