Opera 12 is now in Beta, meaning it's ready for wider testing. If you're an Opera fan, there's no reason to skip this, Opera 12 Beta will install alongside your regular release and have a different profile. If you're not an Opera fan, there may be something in here you'll like.
There are plenty of changes and new features in Opera, from the big and obvious to the subtle.
Hardware acceleration and WebGL, disabled by default
The number one feature in Opera 12 is hardware acceleration and WebGL support to go along with it. Opera has been working close to a year on this one, but it seems that the team has hit a snag.
While hardware acceleration is present and working in Opera 12, it's not enabled by default
and won't be in the final release either. Opera found that the implementation was actually slower than the software backend Vega which it's been using so far.
As such, Opera decided to disable the feature in the default configuration. Users can enable it and WebGL which is also disabled by default via opera:config.
Opera's implementation of hardware acceleration is probably the most complete compared to other browsers, everything on the page and even the UI is rendered via the GPU. But this approach has proven more challenging, unsurprisingly.
If you do enable the features, don't be surprised if things go wrong, this is beta software and the features are not deemed stable enough to be enabled by default. And if something does go wrong, you're stuck, since the entire UI is run on the GPU errors will mess up the page as well as the interface.
Native 64-bit builds for Windows and Mac
Also on the technical side, Opera 12 marks the debut of 64-bit builds for Windows and Mac
OS. Linux/FreeBSD users had access to a 64-bit version of the browser, but one is now available for the more mainstream operating systems as well.
The native 64-bit version should run a bit faster in some cases and will enable the browser to use more memory than before, though few hit the 32-bit memory allocation limit.
Flash and other plugins run in a separate process
Another very interesting feature is out-of-process-plugins. Opera now runs plugins like Flash in a separate process, meaning that a plugin crash won't take down the entire browser.
Likewise, the 64-bit Opera can now use a 32-bit plugin, the major hurdle that prevented the software maker from releasing a 64-bit version for Windows and Mac sooner.
OoPP should also contribute to security, but keeping plugins a bit more separated from the browser, though this is no replacement for a sandbox.