Opera Software, the company behind the similarly named web browser, has rolled out Betas of the latest browser version, Opera 10.5. Starting with the Microsoft developed Windows operating system, Opera 10.5 Beta 2 is now available for download.

This second Beta, as the Opera team explained, “contains many significant improvements over the first beta.” Speaking of which, here is what Opera 10.5 Beta 1 had to offer:

• The user interface has been overhauled to offer a minimalist, sleek design with maximum browsing space.
• Thanks to private browsing you can surf the web safe in the knowledge that Opera 10.5 will not store any info about your session.
• Smarter address field that displays matching results from history, bookmarks and “even actual content on the pages you have visited.”
• The new Search field lets you use different search engines and Web-site searches.
• Windows 7 support
• Run Opera widgets as a separate process, out of the browser.
• Improved JavaScript performance – 8 times faster than the JavaScript engine in Opera 10.10

And now here is what Opera 10.5 Beta 2 for Windows has to offer (highlights):

• Styling of internal pages has been tweaked
• More skin work has been done
• Improved opera:config and overlay authentication dialogs
• Context menu bugs have been fixed
• Widgets bugs have been fixed
• Basic Web Storage user interface

The complete changelog is available here. Opera 10.5 Beta 2 for Windows is available for download here.

Moving on to the Apple developed Mac OS X operating system, the development team at Opera has released Opera 10.5 Beta for Mac. This is the first Beta of the Mac version and it comes with the following:

• Cocoa
• Unified toolbar
• Growl notifications
• Multi-touch gestures
• An undisclosed Easter egg

The complete changelog is available here. Opera 10.5 Beta 1 for Mac is available for download here.