Google Friend Connect was previewed at a Campfire One gathering of third-party software developers at the company's "Googleplex" campus in Mountain View, California.
The unveiling of the plan comes just days after top social networking websites MySpace and Facebook broke down walls of their online communities to let members share profile information at other websites.
"Social is going mainstream," Google director of engineering David Glazer said during a conference call with reporters.
"What used to be hard and proprietary is becoming easy and open. It's the evolution of social networking."
Glazer described the MySpace and Facebook announcements as "big steps forward in giving users control over their data" and said Friend Connect is intended to further advance the movement.
"We see the web moving toward an end state where people can use any application on any website with any of their friends," Glazer said.
"Social activity on the web has been bottled up in a handful of sites. As things mature on the web they become more open and more interoperable."
Friend Connect lets website owner's add social-networking features such as registration, member galleries, message boards, and fun or useful third-party applications called "widgets" by simply adding snippets of free computer code. More>>