After changing its stable release policy to a more accelerated pace, Mozilla released Firefox 5 pretty quick after the latest major Firefox version was put out. Firefox 4 was released on March 22, 2011 and this version follows only three months later. Here’s an announcement on the Mozilla Blog website.
Not long ago Mozilla changed the release cycle of Firefox, so that major new versions (Firefox 5, 6 and so on) will be released every 2-3 months. Currently, the latest alpha release is Firefox 6 Aurora, while the latest beta development version is Firefox Beta 5, which has made it into the Firefox Next PPA already. Installing this version should be very easy if you follow the next steps.
Firefox 4 is knocking at the door and the latest beta release looks just awesome. The seventh beta release introduces several important changes, including a revamped user interface (with the tab location above the address bar and navigation buttons), tab grouping, improved bookmarking system, re-open recently closed windows, built-in synchronizing system, rendering engine improvements, and more. This article contains a screenshot gallery with all the main features and changes brought until now by Firefox 4.