Opera 11 Stable version has been released with many new features most notable of which is extension support that has been missing from it for quite a time.
A look at new features in Opera 11:
Tab stacking allows you to group multiple tabs by simple drag and drop action. Tabs that are grouped under one single tab can be accessed by simply hovering the mouse pointer over the tab.
Safer Address Field
Provides easy, one click security information from simple security badges near the address bar.
Visual Mouse Gestures
Holding down right click displays a visula guide for mouse gestures.
Opera finally gets extension support with as many as 200 extensions available as of now.
Download Opera from here