The biggest new feature of Firefox 54, the one that makes it “the best Firefox ever,” is support for multiple content processes (also known as e10s-multi). In other words, Firefox 54 is the first release of the web browser to use multiple operating system processes for rendering web page content, making it faster and more reliable. Apart from shipping with support for multiple content processes, Firefox 54 simplifies the download status panel and button, adds support for the Burmese (my) locale, moves the mobile bookmarks folder to the main bookmarks menu to give user quicker access to their favorite web pages, and fixes security issues.