Opera released Opera 9, available in 30 languages and including many new features: support for BitTorrent, widgets and site preferences.Since the first beta many things have changed in Opera, and not for the better. Widgets can be accessed in the Widgets menu and every widget creates a new entry in the taskbar. Unfortunately, you can't control the window from the taskbar. Widgets have a smoother font, but are somewhat buggier that in the beta version.
Some sites that still don't work: the chat in Gmail, Yahoo Mail Beta, Google Calendar, Blogger's toolbar (that worked in find in Beta 1).
Opera 9 implements many features available in Firefox and tries to catch up in the market share arena. Unfortunately, Opera seems to duplicate Firefox's memory problems: Opera 9 uses more RAM than ever.
On the bright side, there's Atom support, Web Forms 2.0, SVG, improved security and better XMLHttpRequest support.
* Download Opera 9
* Opera 9 changelog
* Google Operating System widget
Related:
10 features you'll only find in Opera
What's new in Firefox 2