Bebo, a popular social-networking site based in the UK, also announced its own Open Application Platform, with an application programming interface (API) for third-party developers. Bebo has partnerships with more than three dozen developers -- including NBC Universal, NBA, The Gap, and Yahoo -- who are creating music-, movie-, and photo-sharing applications for the site's 40 million users worldwide.

In a statement, Bebo noted it would "be the first in the industry to implement the standards defined by the Faceook Platform." But it also said that it will be compatible with the other major platform for social-networking sites, OpenSocial, and thus become the first to support both.

Facebook and OpenSocial

OpenSocial is a Google-led effort to provide open APIs for social-networking sites, and is now positioned as the main alternative to an open Facebook platform. Other sites that have said they will support OpenSocial include MySpace, Hi5, Plaxo, Ning, and Friendster.

But "there are concerns that OpenSocial is behind the ball" as an alternative to Facebook, according to Forrester senior analyst Jeremiah Owyang. The latest word, he noted, is that OpenSocial will release proofs of concept in early 2008.

He described the current situation as having "a lot of fragmentation," given that many of the announcements are relatively recent. But, he noted, even with widely available standards for distributing third-party applications, developers likely will need to tweak their products for each site because there will be some technical interface or social differences among different sites.

"The expectation that every application will work similarly on every site is over-optimistic," Owyang said.

Into the Enterprise?

If interoperable social-networking applications become widespread, consumers could have their own expectations about what widgets they can use when they go to work. The momentum for interoperability of applications between consumer-based, social-networking sites clearly has the potential to roll over into the enterprise , noted Forrester analyst Rob Koplowitz.

Business-oriented, social-networking tools could also benefit from interoperability, Koplowitz said, such as an ability to exchange calendaring or collaboration tools. He said I.T. departments seem willing to accept third-party applications if they meet their standards for security and privacy, or to allow employees to use business-related applications on external sites, such as Facebook or the more professionally oriented LinkedIn.

Earlier this week, LinkedIn said that it would provide a platform for third-party developers called Intelligent Applications. As with Facebook, outside developers could create applications for the site, but, because LinkedIn is a professional, business-oriented site, it is keeping more control over which applications it allows in. "We're not going to have people sending electronic hamburgers to each other," CEO Dan Nye told the New York Times.

LinkedIn's first announced outside app will allow site users to hover over company names on BusinessWeek, and see a list of people on LinkedIn who have some connection to that company.