Setting up the development environment

First, we need to set up a file structure for our add-on, so let us begin by creating a new folder on the computer. C:\DDG_ addon in our case is the add-on folder. Now, inside that new folder, create a folder called content.

In root directory of our add-on folder, create two new empty text files, called install.rdf and chrome.manifest, and in the content folder, create a new empty text file called ui.xul and an empty JavaScript file logic.js You should end up with the following directory structure: install.rdf chrome.manifest content\ • logic.js • ui.xul

Here, the code is written in XML. The file consists of general information about the add-on such as its version number, name, description, the version of the Firefox browser it supports, the creator of the add-on, etc. sample@example.net is the ID of the extension. It can be your email address.