Mozilla plans to unveil the Firefox 63.0 web browser on October 23, 2018, but you can download it right now if you want to be one of the first to use it on your Linux, Windows, or Mac computer. Mozilla Firefox 63.0 continues the “Quantum” series of the popular open-source web browser with a set of new features and improvements. Highlights of the Mozilla Firefox 63.0 release include support for running WebExtensions in their own process on Linux, which could mean the web browser would consume less memory and CPU usage, and the ability to warn users when there’s several tabs and windows open when attempting to quit the browser from the main menu.