Mozilla has released Mozilla Firefox 4, the newest version of the free, open source Web browser. According to the folks at Mozilla, it's the fastest version of the browser yet.

Firefox is purportedly between two and six times faster than previous releases. Eenhancements to the JavaScript engine make everything from startup time to page load speed to graphics and JavaScript performance faster.

The latest version of Firefox introduces a sleeker look and features like App Tabs and Panorama. Firefox 4 also delivers privacy and security features like Do Not Track and Content Security Policy to give users control over their personal data and protect them online.

Firefox Sync gives users access to their Awesome Bar history, bookmarks, open tabs and passwords across computers and mobile devices. Firefox also offers thousands of add-ons, extensions and Personas and a new Firefox Add-ons Manager to make it easy for users to manage and discover add-ons to customize their Web experience.

Firefox supports modern Web technologies, including HTML5. Version 4 is available to download for Mac OS X, Windows and Linux systems in more than 80 languages. Firefox 4 will also be available on Android and Maemo devices soon.