This book is designed to help you get the most out of your installation of Firefox. Don't have Firefox? You can download it from Mozilla's website.
While we, the maintainers of this book, strive to future-proof our texts, things can change, and in the software industry, change happens often and quickly before writers have a chance to catch up. For example, this book was written when Firefox was still on Windows XP, an operating system Firefox no longer supports (along with Vista, and both operating systems haven't received Firefox updates since August 2018). If you're still on Windows XP or Vista, Mozilla recommends that you upgrade to Windows 7, 8, 10 or 11. Alternatively, you can switch to a Linux distribution.