Facebook becomes hub for outside software makers

SAN FRANCISCO (Reuters) - Facebook.com on Thursday took the wraps off its highly anticipated makeover from a members-only club into what it hopes can allow it to become a software operating system for all sorts of Internet media.

The college student social networking site, which opened up to users of all ages over the past year, said it has signed up 65 partners, including Microsoft Corp. and Amazon.com Inc., to build Web applications within Facebook.

Other companies building services within Facebook include photo-sharing site Photobucket, multimedia presentation site Slide, music discovery site iLike, new-style instant messaging site Twitter.com and Web-calling companies Jajah and Jaxtr.

Founded in 2004 by then-undergraduate Mark Zuckerberg as a socializing site for fellow Harvard students, Facebook now has 24 million active users and is growing by 3 percent a week.

The company, which operates under the radar of much of the traditional tech industry, is looking to transform itself from a Web site into what Silicon Valley calls a "platform" -- a foundation service on which many other applications can run.

The No. 2 social network site, behind News Corp.'s MySpace, will allow developers to build services that work both inside Facebook's site and on their own independent sites.

"Until now, social networks have been closed platforms. Today, we're going to end that," Zuckerberg, Facebook's 23-year-old CEO, told a gathering of software developers.

Facebook has developed a fanatical following, despite going relatively unnoticed by many users on the wider Web. Half of its users, or 12 million people, return daily to the site to check on what their friends are saying and doing.

Zuckerberg cited industry data showing how Facebook is now the sixth-most-trafficked U.S. Web site. Recently, growth has surged in Britain. One in ten Canadians has joined Facebook.

The company made these announcements at "f8," a carefully orchestrated event in San Francisco for 750 developers with more the air of a college job recruiting fair than a trade show. It featured an eight-hour "hackathon" showcasing software built by Facebook engineers and partners.

Facebook aims to be a central clearinghouse for software developers, borrowing a few pages from the decades-old strategy playbooks of Microsoft or IBM, while retaining the flexibility of the new generation of Web-delivered services.

For example, Amazon.com has developed "Book Reviews," an application that allows Facebook members to write book reviews, share what they have written with people in their private social networks, and even buy the books on Amazon.com.

Facebook itself has created a video application that allows any user with a Web-connected camera or mobile cameraphone to share live, personal videos with their network of friends on Facebook. Cameraphone users can shoot video on the go and the video instantly will appear on their Facebook profile.

The Palo Alto, California-based company has created a new Web programming language of its own called Facebook Markup, a variant of the basic Hypertext Markup Language (HTML) coding that underlies all Web pages, with a few special features.

Independent developers can sell ads or incorporate tools for conducting online transactions and keep all the resulting revenue, said Zuckerberg, casually dressed in surfer sandals.

Executives of Facebook, which in November was widely reported to have rebuffed a $1 billion take-over offer by Yahoo Inc. <YHOO.O, were asked at a news conference whether the company would consider selling out to a bigger media company.

"I already thought Facebook should remain independent," Zuckerberg said. "This (announcement) just strengthens that."