Mozilla has released Firefox 4 for OS X, Windows, and Linux.
“Firefox 4 is the fastest Firefox yet. With dramatic speed and performance advancements across the board, Firefox is between two and six times faster than previous releases. Major enhancements to the JavaScript engine make everything from startup time to page load speed to graphics and JavaScript performance screaming fast in Firefox.
The latest version of Firefox introduces a sleek new look that lets Web content take center stage. With features like App Tabs and Panorama, Firefox makes it easier and more efficient to navigate the Web. Firefox delivers industry-leading privacy and security features like Do Not Track and Content Security Policy to give users control over their personal data and protect them online.”
More info: http://www.mozilla.com/en-US/firefox/new/