The latest stable version of Opera 11 debuts today with a faster Turbo, an expanded Speed Dial, and some plug-in tweaks. Opera 11.10 for Windows (download), Mac (download), and Linux (download), also makes a handful of other changes to the browser, notably adding in more HTML5 support, mail client improvements, an updated rendering engine, and better battery management on laptops.

The version of Turbo that debuts in Opera 11.10 is up to four times faster than before, according to the company.

The changes to Opera Turbo and Speed Dial are the most apparent changes in Opera 11.10. The Norwegian company says that Turbo is four times faster than before, and Opera spokesman Thomas Ford said that those speed improvements are likely to filter down to Opera's mobile versions since the improvements were made to Turbo's servers. The gains were achieved in part by adopting support for Google's WebP image format, which resulted in higher image quality in Turbo mode. This still allowed sites to render 35 percent smaller and 15 percent faster than in Opera 11, according to Opera's internal benchmarks.

Speed Dial, the feature that Opera developed to show frequently visited site thumbnails in a grid format, can now be configured to show an unlimited number of dials. The layout is customizable, and a new slider helps users zoom to show more or fewer dials by default.

Other changes include the improved plug-in support that now offers to download and install plug-ins like Adobe Flash if missing from your system, a feature long-present in other browsers' partial HTML5 File API support, which means that Opera ought to be added soon to the list of official browsers that support Gmail' Web Open Font Format support, for next-generation font rendering' and search hijacking protection.

Speed Dial can now handle an infinite number of thumbnails, and can be zoomed in or out.

IMAP has been improved in the built-in Opera Mail e-mail client, so that it better manages "special status" folders such as Trash, Spam, and Sent Items. You can read the full changelog for Opera 11.10 here.