Mozilla Firefox is a fast, light and tidy open source web browser. At its public launch in 2004 Mozilla Firefox was the first browser to challenge Microsoft Internet Explorer’s dominance. Since then, Mozilla Firefox has consistently featured in the top 3 most popular browsers globally. Although the browser's market share is lower for OS X, it is still one of the most popular browsers available on the Mac platform. The key features that have made Mozilla Firefox so popular are the simple and effective UI, browser speed and strong security capabilities. The browser is particularly popular with developers thanks to its open source development and active community of advanced users.
Mozilla put of a lot of resources into creating a simple but effective UI aimed at making browsing quicker and easier. They created the tab structure that has been adopted by most other browsers. In recent years Mozilla has also focused on maximizing browsing area by simplifying toolbar controls to just a Mozilla Firefox button (which contains settings and options) and back/forward buttons. The URL box features direct Google searching as well as an auto predict/history feature called Awesome Bar. On the right side of the URL box there are bookmarking, history and refresh buttons. To the right of the URL box is a search box which allows you to customize your search engine options. Outside of that a view button controls what you see below the URL. Next to that you have the download history and home buttons.
Mozilla Firefox was the first browser to introduce a private browsing feature which allows you to use the internet more anonymously and securely. History, searches, passwords, downloads, cookies and cached content are all removed on shutdown. Minimizing the chances of another user stealing your identity or finding confidential information. Content security, anti-phishing technology and antivirus/antimalware integration ensures your browsing experience is as safe as possible.
Personalisation & Development
One of the best features of the Mozilla Firefox UI is customization. Simply right click on the navigation toolbar to customize individual components or just drag and drop items you want to move around. The inbuilt Mozilla Firefox Add-ons Manager allows you to discover and install add-ons within the browser as well as view ratings, recommendations and descriptions. Thousands of customizable themes allow you to customize the look and feel of your browser. Site authors and developers can create advanced content and applications using Mozilla’s open source platform and enhanced API.
Better recommendations: You may see suggestions in regular browsing mode for new and relevant Firefox features, services, and extensions based on how you use the web (for US users only)
Enhanced tab management: You can now select multiple tabs from the tab bar and close, move, bookmark, or pin them quickly and easily
Easier performance management: The new Task Manager page found at about:performance lets you see how much energy each open tab consumes and provides access to close tabs to conserve power
Improved performance for Mac and Linux users, by enabling link time optimization (Clang LTO). (Clang LTO was enabled for Windows users in Firefox 63.)
More seamless sharing on Windows: Windows users can now share web pages using the native sharing experience. You can access Share in the Page Actions menu
Added option to remove add-ons using the context menu on their toolbar buttons
New for enterprise users: Updated the policy engine on macOS to allow using configuration profiles to customize Firefox for enterprise deployments
Various security fixes
RSS feed preview and live bookmarks are available only via add-ons
TLS certificates issued by Symantec are no longer trusted by Firefox. Website operators are strongly encouraged to replace any remaining Symantec TLS certificates as soon as possible.
about:crashes has been redesigned to make it clear when a crash is being submitted to Mozilla, as well as being clear that removing crashes locally does not remove them from crash-stats.mozilla.com
The macOS keyboard shortcut to add "www" and ".com" to a URL is now ctrl-enter instead of ⌘[cmd]-enter