JSView is a Firefox extension to view the source code of external files. Most websites store their Javascripts and style sheets in external files and then link to them within a web page’s source code. All browsers include a “View Source” option which is not able to view the source code of external files. Previously if you wanted to view the source code of an external Javascript/CSS you would have to manually look through the source code to find the url and then type that into your browser, or open it with Notepad/WordPad.

With JSView installed in Firefox, you can access Javascript/CSS external files from the context menu, from the toolbar, from the view menu, or from the status bar.

The ‘view page source’ menu item now opens files based on the behavior you choose in the jsview options. This allows you to open the source code of any web page in a new tab or in an external editor.

For more information, you can visit the Homepage of JSView. Get the latest version of JSView from https://addons.mozilla.org/firefox/2076/.