Recently I have changed from using Google Chrome to Firefox and I have to say that even with the recent release of Chrome I have not moved back.

Firefox 4 has now been released and is available for download. some of the changes include:

Fastest Firefox Ever
Performance: Firefox is up to six times faster than the previous release. With improved start-up and page load times, speedy Web app performance and hardware accelerated graphics, Firefox is optimized for rich, interactive websites.

Streamlined Interface
App Tabs: give a permanent home to frequently visited sites like Web mail, Twitter, Pandora, Flickr.    Switch to Tab: easily find and switch to any open tab from your Awesome Bar without opening duplicate tabs.    Panorama: drag and drop tabs into manageable groups to save time while navigating many open tabs.

Private and Secure Synchronization
Firefox Sync: access your Awesome Bar history, bookmarks, open tabs, passwords and form data across multiple computers and mobile devices.

Most Customizable
New Add-ons Manager: easily discover and install more than 200,000 add-ons to customize the features, functionality and look of Firefox.

Private and Secure
Do Not Track: Firefox is leading the Web towards a universal standard Do Not Track feature that allows users to opt-out of tracking used for behavioral advertising.    Firefox puts privacy first, fixing flaws in some Web standards to prevent others from accessing your browser history.    HTTP Strict Transport Security (HSTS): automatically establishes secure connections to stop “man in the middle” attacks and keep sensitive data safe from interception during the log-in process.    Content Security Policy (CSP): prevent cross-scripting attacks by allowing sites to explicitly tell the browser which content is legitimate.

You would be surprised by the performance difference a browser can make and during the past six months of testing our new Red Square Web product we have found Firefox and Chrome to perform much faster than Internet Explorer.