In an effort to break into the browser big leagues, Opera Software, maker of the innovative but little used Opera browser, on Tuesday introduced a new version of its software called Opera Unite that combines Web browsing with file serving.

Opera Unite takes cloud computing and turns it into crowd computing. That is, it removes the need for a Web server and allows people to share files and interact directly. "PCs decentralized computing away from large mainframes," Opera CEO Jon von Tetzchner said in a statement. "Opera Unite now decentralizes and democratizes the cloud."

"This technology is a radical first step towards addressing what I call 'the Internet's unfulfilled promise,' which is about our ability to connect with each other and participate meaningfully online -- on our own terms, and without losing control of our data," said Lawrence Eng, a product analyst with Opera Software, in a blog post.

Opera Unite allows users to share files by generating a direct URL to the hosting computer. It lets users host entire Web sites, music playlists, and photos. It also supports a chat service and a note-exchange system.

Eng describes Opera Unite as enabling a new class of social Web applications. The software, he says, allows users to "connect directly without needing middlemen who control third-party servers."

For all the middlemen and content aggregators out there who profit from the control of third-party servers and the ads delivered there, you've been put on notice.

Initially released in 1996, Opera has never really taken off among consumers, though a mobile version is installed on roughly 40 million mobile phones around the world. Opera for computers has a global market share of 0.72%, according to Net Applications. Google Chrome has more than twice as many users, only nine months after it launched.

Opera Unite could change that dynamic, though it will be a significant challenge to steal market share from Apple, Google, Microsoft, or Mozilla without the backing of a powerful distribution partner or a community of committed open source advocates.

There's another consideration, too: security. Sharing files and running a Web server can put the host computer at risk. Michael Sutton, VP of research at Zscaler, worries that attackers will be able to leverage Opera Unite to spread malware, conduct social engineering attacks, and/or steal personal information.

Milw0rm, a site that hosts proof-of-concept exploit code, lists five Opera vulnerabilities identified in 2008 and one identified in 2009. There are likely to be more and such vulnerabilities could become more severe with the built-in file-sharing capabilities of Opera Unite.

There are also reasons not to serve files from one's home computer that are unrelated to security, such as limited upstream bandwidth and resource usage.

At the same time, Opera Unite deserves consideration for challenging the cloud computing orthodoxy. It's interesting technology, to say the least.

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