Other functionality that can be replicated via plug-ins includes Facebook's activity stream and log-in operation as well as a new recommendation engine to generate personalized recommendations for site visitors.

While Facebook has been moving toward this vision for some time, the company has now significantly simplified the tools and processes for developers to build applications and Facebook integration into their sites, said Bret Taylor, head of Facebook Platform products. "The Facebook platform can be both powerful and simple," he said.

Among the partners joining Facebook in Wednesday's announcement is Microsoft, with which it built a joint site called for Facebook users to collaborate on online documents. This, at first glance, looks like it could compete against the similarly named Google Docs suite of hosted office productivity applications. Other partners include customer review site Yelp and music site Pandora.

Facebook's goal is to move from a Web that's connected via hyperlinks to one "where the default is social" and has users with real identities at its center, Zuckerberg said.

Neither Zuckerberg nor Taylor spoke much about the implications, if any, of the announcements on users' privacy, always a big question for Facebook, where people store and share a lot of very personal information and content.