Mashable: "Mozilla’s rapid release schedule for Firefox continues with the arrival of Firefox 7 for Mac, Windows and Linux.
Firefox 7 comes less than six weeks after the release of Firefox 6. Mozilla moved to a more rapid release cycle with a more streamlined, frequent and incremental upgrade cycle a la Google’s Chrome browser, after Firefox 4 launched back in March.
As a result, most of the changes have taken place under the hood. Mozilla boasts that Firefox 7 uses less memory and performs faster."