The result isn't as messy as it may sound - in fact, it could become a must-have for tabaholics who typically keep a dozen or more tabs open at any time. But is it useful enough to get you to switch?

To stack tabs in the new Opera 11 beta, you simply drag and drop. Tabs can be stacked any way you like - by site, by group, by theme, by favorites, etc. Then, when you hover your mouse over a tab, the stack expands in a visual preview. You can then click an arrow icon to expand the stack across the tab bar.

Here's a video demonstrating the feature in action (at the 0:50 mark):

In practice, I have to admit, there were a lot of drag-and-misses going on at first. Tabs weren't immediately stacking as easily as they should, they were just changing positions with each other. I realized that I was only able to stack tabs when dragging them from left-to-right, not right-to-left. In watching the demo video, that appears to be by design. That's an odd choice, in my opinion. It's not how I'd imagine this feature to work. When you click links on a Web page, tabs shoot out to the right of the tab you're currently on. It would only make sense to then drag those newly opened tabs back on top of the source tab. But that's not the case.

That being said, when I figured out how Opera wanted its tab stacking feature to work, it was easy to see the usefulness of stacks. It could definitely streamline your workflow...or even better, hide your non-work related Web surfing from the boss. (Not that we bloggers have that problem - Web surfing is always work-related!)

As a self-confessed tabaholic myself, this is one of the first features that has really grabbed my attention from Opera (even despite the initial bugginess) as I could immediately grasp the potential impact on my day-to-day Web research and browsing behavior. Returning to Chrome with its 20 or so open tabs all of a sudden felt busy, cluttered and disorganized. Maybe there's a Chrome extension to fix that?

Other New Features

Tab stacking isn't the only new feature in Opera 11. The updated beta also introduces the following:

• The address field now hides unnecessary information and puts the security status of each page front and center. Now, badges explain the security state of the site, giving consumers clear information about the sites they visit.
• Plug-ins can be set to load on-demand. This can give as much as 30 percent performance improvement.
• Extensions and Opera Unite applications are updated automatically through Opera's update mechanism.
• Even more work has been done to boost browsing speed, particularly for Linux. Opera 11 for Linux is 15 to 20 percent faster on common benchmarks than Opera 10.63.
• Bookmarks are just a click away thanks to a new bookmarks bar that replaces Opera's personal bar.
• Opera 11 is 30 percent smaller than Opera 10.63, despite including new features.

You can download Opera 11 beta from here.

Tabs on Top

The "tabs-on-top" feature is still experimental and doesn't come with the final user interface (go to view - toolbars - tabs on top to enable them). Currently, these tabs look just like your regular Firefox tabs, but in the final version, they will be fully integrated into the browser's interface. This developer preview also features a new interface for managing addons and themes.

Mozilla also points out that this it the first browser with full support for parsing HTML5 according to the specification.

You can find the full release notes here and our overview of Mozilla's plans for Firefox 4 can be found here.

Speed: Still Trails in Benchmarks - But Feels Faster than Chrome

In most benchmarks, Chrome still beats Firefox. More importantly, though, this current preview version actually feels faster than the latest developer versions of Chrome. Thanks to implementing lazy frame construction, the developer preview version can render complex dynamic pages faster, which is especially apparent on large newspaper websites and other complex pages.

Mozilla Labs posted a new proposal today to put frequently visited page thumbnails in the very corner of new tabs and to perform contextual actions automatically, based on what you were doing on your last tab. For example, if you've highlighted a street address on one tab, Firefox might open a map of that address automatically in a new tab.

What would you like to see open automatically in new tabs?

The Proposal

The image above is what's been proposed. Aza Raskin of the New Tab design & prototype team writes that this is clearly just a proof of concept, but you can test it out now by following the instructions in his post. You can see that there's an undo option for closed tabs, a one click option to search for a highlighted term, screenshots of most-visited pages and their RSS feed headlines displayed when available. All in maddeningly light grey.

This isn't something I'd use, but maybe others will like it.

The Opera and Chrome browsers have nice big "speed dial" pages in blank tabs, though neither of those options is as hot-looking as the new Safari speed dial page!

I've tried having RSS feeds display in new tabs, but I never really looked at them. I wouldn't mind having "inspiring images" appear randomly from Flickr, for example, but that would get distracting. Friends' activity streams might not be so bad.

For now though, I think I prefer to keep my blank tabs...blank. It might be nice if they were black and not white, in fact. It's almost a spiritual thing. I'm not sure I need stuff in there, I like the infinite potential of the fresh, blank new tab.

Says Beltzner, the goal is to have tabs that are related grouped together. The change will be landing on the trunk shortly and then they will decide whether or not to take it to Firefox 3.1. (Please do!)

Tabs, tabs, everywhere

The tab ordering feature is one of the little things that doesn't get a lot of attention when people talk about Google Chrome. Instead, the focus is on the WebKit engine, the lightweight feel, the speed, and, of course, the lack of RSS (the horror!). However, if you often switch between Chrome and Firefox, you're probably frustrated when you start opening tabs in Firefox and they end up at the end of a long list of your open sites, forcing to you to scroll to see them.

Getting tab ordering right is not as minor as it seems. When it's right, it "just works" and you don't even really have to think about it. Minor features like this are the sort of things that you can't quite put your finger on when people ask you why you prefer your Chrome browser - you just know that you like it better. It just seems easier to use in some way.

Chrome showed us how tab ordering should work and we can't wait to see Firefox adopt this useful feature.