Opera hired designer Jon Hicks to spice up its interface, which is a work in progress in the beta, according to Hicks. "Initially, we were just going to clean up some elements and focus on the interface for new features," he said in a statement. "But, over time, the new user interface elements became so different that we decided to update everything. Mac users in particular should enjoy this update to the default Opera skin."

Opera owns just 0.7 percent of the browser market share, a space dominated by Microsoft's Internet Explorer (65.5 percent) and Firefox (22.5 percent), according to Net Applications, an Aliso Viejo, Calif.-based company. Safari (8.4 percent) and Chrome (1.8 percent) also garner more share than Opera; Netscape has 0.7 percent share.

Opera 10 will feature a new compression technology called Opera Turbo that delivers up to four times the speed of slower connections and can offer "broadbandlike speeds on dial-up," according to the company.

Other new features include visual tabs, an inline spell checker that supports 51 languages, and users' choice of Web mail providers, online feed readers and multiple Bit Torrent clients.

"Your Web browser is the most important piece of software you will ever use," said Jon von Tetzchner, CEO of Opera Software, in a statement. "We think Opera 10 will redefine how you can enjoy the Web. We have more surprises on the way, but when you try the features, enjoy the accelerated performance and get a glimpse at our shiny new wrapping, I think Opera 10 beta will excite both longtime users and those new to Opera."