The Firefox 4 Beta is now available for free download, and Mozilla’s urging people to get the word out so they can successfully field-test it. Giving feedback is easy with the Test Pilot Feedback Add-on, where you tell Mozilla whether Firefox made you feel “happy” or “sad” and why. But what exactly is Firefox 4, and why should you care?One noticeable change is the look of the browser. This is designed to make sure you don’t lose track of the many options Firefox offers. For example, tabs (the feature that allows you to have multiple pages open in one window) are now located at the top of the screen. Switching tabs is also made simpler with the addition of a toolbar option. The menu itself is cleaned up, with all options now available in the Firefox buttonsimilarly to the Microsoft Office 2007.Privacy is also upgraded to eliminate some loopholes within web standards. Among other things, the new browser will give false values to functions like getComputedStyle() and querySelector. Before, these were used by developers to see how many times a user has visited a website, and where that visitor has been previously. Now Firefox users will be more protected than ever.A number of other changes in the coding and development of the browser make it more fluid and developer-friendly. WebSockets are a godsend for developers who want to integrate real-time online events, such as gaming or chatting. New CSS3 features like Transitions and Transformations add developers who want to add animations to their pages. Plus, a cutting-edge HTML5 parser provides support for the newest in internet technology, meaning no app will be left incompatible.You can be sure that Firefox will be adding new features as time goes on (they’ve already announced some), so make sure you get in on the ground floor by downloading the beta today.