Opera Labs released a pre-alpha release of Opera 10.50, which has been in development for over 18 months. Sporting many changes, Opera Software released this build as a preview of things to come, thus it's not feature complete, nor stable.

For Linux users it may come as a disappointment that their platform will not receive a labs build at this time (surely it will come later), but those with Windows and Mac will be surprised by the goodies inside, specific for their platform.

Presto, Carakan and Vega
Long ago there was a story on this site on how Opera Software was able to rewrite their rendering engine in a matter of months, starting with only two developers. In comparison it took Mozilla many years and many people to come to something useful. Likewise Presto is still one of the cutting edge rendering engines out there that, like WebKit, allows itself to be ported to any platform, from desktop to mobile. So it's no surprise, and certainly hot news that Presto has been updated to 2.5 (Opera 10.10 comes with Presto 2.2) and includes a lot of much requested features (and standards support): CSS transformations, HTML5 local storage, and much more.

But that's not even the most exciting part. Carakan is here! Futhark has been the JavaScript engine for Opera for a long time, but it has been showing its age. Futhark was designed to be sparse on resources, while today we want maximum execution time. Following in the footsteps of Chrome's V8 and Safari's Nitro, Carakan is a JIT compiler based engine that shows 7x higher performance than Opera 10.10 on Windows with SunSpider. The folks at Opera Labs already note that on Mac this is less due to missing optimizations.

Vega, the new library used to render SVG and canvas elements has been extended to be the de-facto graphics rendering library. Although it is promised to use hardware rendering, the current implementation uses software rendering instead. But don't sweat, it will become hardware accelerated, but just not right now, as it's an early build. Peacekeeper, the benchmark from FutureMark shows even with software rendering an increase in performance of 3x.

Platform integration
Now that's a topic of lots of discussion and emotion. Opera has been slow in being platform integration, offering often a good looking cross-platform interface instead. But change is afoot. For Mac they've rewritten it entirely in Cacoa, which is the modern framework. This means nice flashy animations, unified toolbar, the end of the white resize thingy in the right bottom corner and native widgets everywhere. Oh, and the almost mandatory third party software support for notifications: Growl.

For Windows Vista and Windows 7 users the change may even be bigger. Aero support is here, meaning that the top of Opera is now all glassy transparent. The menu is also gone in favor of an application icon, much like Office, Paint and WordPad with the Ribbon interface. For Windows 7 users Aero Peek and Jump List support was added.

Privacy, pr0n
For a while now Opera was lacking behind on privacy, while being the first to offer the "Delete Private Data" option before the competition picked up. However with Safari and mostly by Chrome the option to go to private browsing mode on the fly (not storing anything, but not deleting either) became popular.

Opera Software has now followed the example and introduced private browsing per tab. Yes you read that last bit right, Opera offers private browsing per tab, and in fact more specifically per tab per window. You can seamlessly browse pr0n now while having other web sites open for stocks, weather, news etc.

Caution
As you can imagine this is an exciting release, though you might miss the Opera 10.20 features: stand-alone widgets. But there is some good and less good news. Opera 10.20 will not be continued, instead 10.50 will be favored (this is a good thing). Don't worry stand-alone widgets will return in Opera 10.50 in the course of its development.

I think Opera Software is right back on track in delivering what may be the most exciting browser release of 2010. Following their own ideals of providing an all-in-one package, rather than extensions like Chrome and Firefox, they may actually win new users by providing better privacy features, maximum performance, standards support and real platform integration.

Before downloading do note that this build is pre-alpha, it's really a preview of things to come and should not be used by normal end users. Well, with that out of the way, good luck, and don't forget to report your findings!