Opera Software today released version 11 of its flagship desktop browser, adding a new tab manager and support for extensions.
Opera's last major upgrade, version 10, shipped in September 2009.
The browser's most noticeable addition is "tab stacking," a new way to manage multiple tabs. In Opera 11, users can drag and drop open tabs to create a stack, or collection of tabs, on the tab bar, then preview the contents of a stack or re-open them as separate tabs.
At least one Opera rival has also made changes to help uses handle tab glut. Mozilla debuted its "Panorama" tab manager -- a separate screen that lets users shuffle tabs in an out of groups -- last August in an early build of Firefox 4. Mozilla plans to ship the final of Firefox 4 early next year.
Opera 11 also finalized support for extensions, a feature that the Norwegian browser developer first announced in October just prior to launching an "alpha" preview. The add-ons can be downloaded from Opera's library.
The collection currently contains about 200 add-ons, far fewer than Mozilla's or Chrome's add-on galleries. Among the most popular, according to Opera, are the LastPass password manager -- LastPass purchased the better-known Xmarks bookmark sync service earlier this month -- and a Web ad blocker called NoAds.
When Opera introduced extension support, the company's chief CTO, Hakon Wium Lie, said add-ons were "ripe for standardization," and called on other browser makers to work together.
"We'd like to work with other vendors to make sure that extensions become a true part of the Web," Lie said in October. "We should work together, as we've done with other standards, to make extensions part of that repertoire, that buffet, of standards."
Opera's former CEO repeated the call for standardization today.
"We would like the different browser makers to work together and standardize extensions," said Jon Von Tetzchner, Opera's co-founder and former CEO, in an interview Thursday. "It's very much in line with our thinking about Web standards and makes a lot of sense."
Other modifications to the browser include a tweaked address bar that now shows the security rating of a site and a visual guide to mouse gestures, the small movements of the mouse that the browser reads as navigational commands.