The bottom line: Extensions, highly competitive page-load times, cutting edge features, and strong support for "future Web” technologies make Opera 11 one of the best browsers available.

Review:
The second-oldest browser currently in use, Opera debuted way back in 1995 and has recently undergone a major overhaul. No longer the quirky choice of enthusiasts, Opera has developed into a robust, full-featured suite of browsing tools.

Opera covers the basics with tabbed browsing, mouse-over previews, a customizable search bar, advanced bookmarking tools, and simple integration with e-mail and chat clients. Mouse-gesture support, keyboard shortcuts, and drag-and-drop functionality round out the essentials.

Installation
Installing Opera is a fast and short process, taking less than two minutes. Many of Opera’s built-in features require creating a MyOpera account, but the browser will only prompt you to do so when you use them for the first time–it’s not required to browse.

Tap the "Options” button on the first install screen to reveal configuration tweaks. Besides changing the browser’s default language and install path, you can also install for just the currently-signed on user, or choose to install Opera directly to an external device. It’s a great, simple way to create a portable version of Opera for a USB key.

Interface
Opera’s interface keeps the same look that debuted in Opera 10.50, with a condensed menu button in the upper left corner, tabs on top, and a translucent status bar on the bottom that hosts buttons to reveal Opera’s Panels, and to activate Link, Unite, and Turbo. The bottom right corner of the status bar sports a dedicated zoom button.

Buttons on the navigation bar have been condensed, and are now the same height as the location bar. This gives the interface a polished look, and minimizes the amount of space that the bar takes up. The search box, located in its default space to the right of the location bar, can be removed. That and further interface customizations can be made by right-clicking on the navigation bar and selecting customize.

Extension buttons appear to the right of the search box, as they do in Google Chrome, while a recycle bin for quickly re-opening recently closed tabs lives on the right side of the tab bar.

The influence of the radical interface changes that Google Chrome introduced in 2008 can be seen here, from the tabs on top to the extension icons, yet Opera’s personality does still come through enough to have a different vibe and feel from Chrome.

Features and support
The five major browsers have been liberally borrowing features and innovations from each other for years, yet Opera has developed a reputation for showcasing some of the more interesting browser developments first.

Opera 11 introduces tab stacks, a tab grouping mechanism similar in concept to Firefox 4′s Panorama, but completely based in the tab bar. To use it, drag one tab on top of another. The bottom tab will disappear, and an arrow will appear to the right of the tab. Click it to reveal the stack, and drag a tab off the stack to separate it. Where Panorama’s global viewpoint makes it easy to see all your tab groups, Opera’s tab stacking feels much smoother and more intuitive.

Tab stacks are a tab-grouping mechanism similar in concept to Firefox’s Panorama, but completely based in the tab bar. To use it, drag one tab on top of another. The bottom tab will disappear, and an arrow will appear to the right of the tab. Click it and the tabs in the stack will slide out to one side. To break up a stack, drag a tab off the stack. Mouse over the stack to see previews for all the tabs in the stack.(Credit: Screenshot by Seth Rosenblatt/CNET)

As noted earlier, extensions have finally come to Opera in version 11. Opera uses a lightweight extension framework based in HTML, CSS, and JavaScript to minimize the processor hit that add-ons can incur. If you’re familiar with the extension networks in the WebKit-based Chrome and Safari, you’ll be very comfortable with how Opera handles its add-ons. It’s interesting to note that Opera sees extensions as singing in harmony with their existing Widgets framework, saying that widgets are basically stand-alone Web-based applications, while extensions are for changing the user experience in-browser.

A third big change is the introduction of on-demand plug-ins. This is a feature that has been on the periphery of user awareness for a while, but it’s about to go big as it provides much more control to users over page security and page load times. It’s great for people who are rightly worried about unpatched Flash and QuickTime security exploits, or just want sites to load faster. Go to Preferences, Advanced, then Content to toggle it.

Another change comes to the security badge system, which marks sites as "verified safe”. Click on the gray "Web” globe icon to the left of the URL bar to check a site’s status. Getting information returned was quick on most sites, although it was a bit slow for others. The badges are colored yellow for "secure”, green for "trusted”, and blue for when you’re running Opera’s Turbo mode, another excellent feature that’s designed for assisting people surfing on slower connections. The Turbo badge will also display estimated data savings. You can turn on Turbo using the button in the status bar at the bottom left of the browser.

Opera’s site badges also include a useful reporting mechanism, so it’s easy to report a site as fraudulent or malicious.

With plug-ins disabled, click the "play” triangle and the plug-in content–in this case, Flash video–will start playing.(Credit: Screenshot by Seth Rosenblatt/CNET)

There have been some smaller tweaks to the browser, too. Pinning a tab will now jump it to the left of the tab bar, as is done in other browsers. The personal bar has been replaced, too, by a bookmarks bar, both pulling the browser into parity with the competition and making bookmarks accessible with one click.

Opera’s extras push it to among the top of the class. Opera’s desktop widgets can appear anywhere, and Opera Unite and its deep feature set for file sharing and streaming is now available to Mac users. Quick Find has improved the search tool, allowing for full text searching from the address field, the history panel, and opera:historysearch. We’re also fans of the inline spell checker that supports 51 languages, and the recent addition of the auto-updater. Unlike Chrome’s automatic updates, Opera plays nice with its users and gives you several choices as to how to implement auto-updating, including disabling it.

There’s Growl and multitouch trackpad support on Macs, support for some HTML5 including next-generation video and audio codec WebM, geolocation compatibility, Web Workers, App Cache, and Web fonts. The Web Open Font Format (WOFF), which Opera co-sponsored, hasn’t yet been added, although Opera expects it will be soon. Meanwhile, Opera Link enables Bookmarks, the Personal bar, Speed Dial, and Notes synchronization across all other Opera instances, including the iPhone’s Opera Mini. Opera’s availability on multiple mobile and desktop platforms makes it uniquely appealing as a one-stop browser shop.

One of Opera’s lesser-known features is its integrated mail client. It’s a reasonable alternative to Outlook, offering many similar features. It can handle importing mailbox files from Outlook Express, Thunderbird, Netscape, and Eudora, supports POP3 and IMAP, and quickly synced with Gmail when we added our account.

There are other features in Opera, including tab previews, newsgroups support, a built-in session manager, and a fantastic array of customizations that rivals Firefox. Of all the browsers out there, Opera ships with a massive feature set and is an excellent choice for users who want something fast and robust right out of the box.

Performance
Opera some big performance improvements in this version, and they appear to bear out. In addition to helping some pages load up to 30 percent faster simple by toggling the plug-ins, as described in the features section above, the browser’s performance in general has been improved. Opera says that Opera 11 is 15 to 20 percent faster than Opera 10.63, and that the browser size on disk has been reduced by almost one-third.

Full benchmarks will be added here as they are completed, but preliminary results indicate that Opera 11′s page-load times remain comparable to Google Chrome’s on publicly-available benchmark tests like Google’s V8, WebKit’s SunSpider 0.9.1, Mozilla’s Kraken, and Futuremark’s Peacekeeper.

Conclusion
Opera is in firm grip of the 5th-place slot in the race to be the world’s most-used browser. It doesn’t have the backing of a major corporation like Apple’s Safari, Google’s Chrome, or Microsoft’s Internet Explorer, and it lacks the massive developer’s community of Mozilla’s Firefox. What it does have, and these are recent developments to be sure, are a fantastic combination of speed and built-in services.

Opera undoubtedly has what it takes to unseat even the biggest-name browsers. You just need to hear it sing.