This article explains the basics of creating an add-on for FireFox using the FireFox Add-on Builder and Add-on SDK. Read more about them on the Mozilla website. As an example, I’ll use the GroupDocs add-on. (You can download the source code from Github.) It’s an advanced extension so I’ll focus on the basics and highlight a couple of interesting aspects communication between scripts. I’ll mainly look at the add-on folders data and lib in the /resources/groupdocsviewer/ folder....js file, located in the lib folder,...launched. At the top of the file is a ;ist of libraries linked...