The new tab stacking feature is in the beta version of Opera 11, introduced Tuesday. The new features make it possible drag one tab on top of another to group them into sets. Hovering the mouse over a tab causes the stack to expand into a visual preview, and clicking an arrow icon on the stack expands the tabs across the browser's tab bar.
Tabs that mark individual web pages are among the most popular tools in today's major browsers. However, their popularity has also made them unwieldy in large numbers.
"Because so many of us wrestle with tens or even hundreds of open tabs, we needed a way to simplify tab management," Jan Standal, VP of desktop products for Opera, said in a statement. "Just like stacking papers for future reference, stacking your tabs is an intuitive way to organize and collect your open web pages."
Opera is not the only browser maker taking on the problem with organizing large numbers of tabs. Mozilla, maker of Firefox, has introduced in Firefox 4 beta a feature that lets users group tabs, and then only show selected groups across the tab bar. Originally called Tab Candy, the feature is now called Panorama.
Other new features in Opera 11 include extensions, which are browser add-ons that the user can select to enhance the browser's capabilities. Such add-ons have been a major feature of Firefox for some time.
Opera 11 beta is available for download through the company's website.
The browser market is heating up with Opera, Mozilla, Google and Microsoft all working on next-generation products. Microsoft's Internet Explorer remains the most widely used browser with roughly 60% of the market, according to web metrics firm Net Applications. Firefox places a distant second with 23%. Google Chrome, Apple Safari and Opera share most of the remainder of the market.