Opera Software has released the preview of Opera 15, the first version of its desktop browser to use the WebKit-derived Blink engine. We're still in the early days, with the browser missing features that many Opera users know and love. But it's already taking shape, sharing features with the recently released WebKit-powered Opera for Android. The desktop browser uses Google's WebKit fork, Blink.

The updated rendering engine gives Opera 15 a score boost on things like HTML5test.com, up from 404 to 433 out of 500. A cursory browse of the Web suggests that the new browser does a decent job of rendering webpages.

In many ways, that's the point of Opera's decision to drop its old Presto rendering engine and switch to WebKit. Opera's low market share meant that regardless of the technical merits of its engine, many sites weren't tested with it, so compatibility was always a concern. WebKit doesn't have that problem and Blink shouldn't either, so by changing engines Opera users can expect far fewer issues.

Similarly, Opera is using Google's V8 JavaScript engine. In that regard, performance and compatibility should be consistent with that of Chrome.

If it shares a common core with Chrome, what's the point of Opera? The major points of differentiation have traditionally been the user interface, rich non-browser functionality such as mail and IRC chat, and features to make the most of low-bandwidth connections.

In this regard, Opera 15 is something of a mixed bag. The non-browser extras are gone; Opera has broken the mail client out into a separate application, Opera Mail. The new browser has no IRC client at all. Opera's old DragonFly developer tools are missing, replaced by the WebKit tools.

The old Presto version supported skins/themes; the new version allows you to change the background image on the new tab page but that's about all. The new browser looks really quite Chrome-like. For example, it has a unified address/search bar, it puts its settings page in a tab rather than a modal dialog box, and it has no status bar—though it does keep Opera design elements such as an Opera button with the main application menu in the top left.

The new tab page has three sections. Opera's most distinctive feature, Speed Dial, is the first of these. It shows big tile icons for sites that you visit regularly, with folders so that sites can be organized and kept tidy.

The second section is a new take on favorites/bookmarking: the stash. Hit the heart icon in the address bar and the current page gets put in the stash. Each stashed page is shown with a thumbnail, and searching the stash performs a full text search of stashed pages. So if you come across a page that you think you'll want to refer to later just stash it. You don't have to remember the title or domain of the page, just roughly what it was about. Search for some keywords and it'll appear.

On the third section is Discover, a customizable news feed plucking items from a variety of news resources. The Discover feature was first introduced in Opera for Android. The feature is much the same, with only the presentation slightly different.

Another feature that came first in the Android browser is Off Road Mode. This is the successor to Opera's Turbo mode. It compresses pages to reduce the amount of data that gets downloaded, maximizing the performance of poor connections. While this is more obviously useful in the mobile browser thanks to mobile network performance not always being what it should be, it nonetheless has value in a desktop browser. This is especially true when using overburdened networks at hotels and conferences.

Other Opera features are only partially implemented. Some of Opera's mouse gestures are supported in the beta, but not all of them are. Things like opening new tabs and reloading pages work, but cycling tabs with the mouse wheel and opening links in new tabs don't.

The new version of Opera may be version 15, but it's plainly a new browser. Opera hasn't simply retrofitted its existing shell with a new engine, the company has started development anew. That's why some features that long-standing Opera users might have expected to see, such as that mail client, are missing.

Those users may be disappointed but it's early. The browser may have lost some features but it has gained a more compatible, more widely supported rendering engine. The lost bells and whistles come in tandem with a more robust browser. Opera clearly felt it was a trade-off worth making—the company's task is now to convince its users of the same.

Update: Amended post to note that Opera 15 is Blink-based, rather than WebKit-based.