It seems like Opera might be feeling the heat of the browser wars, and they probably also had features that didn't get implemented in time for 10.5, because they just released the final version of Opera 10.6 only two weeks after the beta release and less than a year after the release of Opera 10.5, which debuted their new high-powered JavaScript engine, Carakan.  They say that this release is a whopping 50% faster than the last version.

Here are some speed tests from the Peacekeeper Benchmark test:



Opera 10.6 includes several new HTML5 APIs along with other web standard implementations.   Here are the news ones:

• Geolocation
• Offline Web Applications
• Web Workers
• Cross-Document Messaging
• WebM
  
  

The Geolocation standard was partially implemented on FreeBSD and Linux, but now it works across all operating systems.  The browser alerts you when a site requests Geolocation information.  You can then accept or deny the request.  

The AppCache for offline applications blurs the line between desktop and web apps.  Opera also plans to build this functionality into their debugging tool, Dragonfly.  You'll be able to debug offline once this feature is implemented.

Web Workers support is in the early stages for Opera 10.6.  This HTML5 standard allows JavaScript to run parallel processes to that the main script can focus on the important things.  There will be a slight speed improvement because of Web Workers, but Opera says the difference won't be that pronounced because Opera is currently a single-threaded application.  As Opera begins to develop a multithreaded version (which would only be supported by certain platforms), the Web Workers will really start to make a difference.

In the UI, Opera has simplified certain tabs like history and home with icons instead of thumbnails.  Mac plugins should perform better in 10.6.  Opera also added support for a few CSS properties with vendor prefixes.  



Linux users will notice that Opera is skipping 10.5x on Linux to get all the platforms in step again.