After a period of beta testing, the final version of Opera 11 has been released, bringing several important improvements, including extensions, tab stacking and visual mouse gestures to the browser.
Tab stacking lets users organize tabs into groups by dragging and dropping tabs onto other tabs, creating "stacks." It goes hand in hand with Opera's many other tab management features, such as organizing tabs into categories or saving them for later.
Extensions let you improve Opera's basic functionality with a number of add-ons available from Opera's extensions catalog.
Other new features in Opera 11 are visual mouse gestures, an improved auto-update system (which now makes sure that your Opera, its extensions and Opera Unite apps are up to date), and a new e-mail panel.
Opera 11 also brings HTML5 support, as well as many performance improvements and memory issue fixes. You can download Opera 11 here.