Punkjs is a Chrome extension developed by Jonathan Cremin. It is a free browser add-on that allows you to load local Javascript files into web pages based on the filename. It is designed to work with the Google Chrome browser.

Punkjs uses the Chrome runtime messaging API to communicate between the extension and the bridge app. When you navigate to a webpage, the extension informs the bridge app about the domain of the page. The bridge app then searches for matching Javascript files, starting from the top-level domain and working down through the levels. The extension executes the returned Javascript code in the context of the web page.

Punkjs requires Google Chrome to function properly. It is a useful tool for developers who want to enhance their web browsing experience by injecting custom Javascript code into specific web pages.