Facebook developers: Open Graph protocol - integrate your Web pages into the social graph - #F8
Facebook has introduced a major redesign of its social feeds and users’ profiles at its annual f8 event for developers in San Francisco. Mark Zuckerberg unveiled a big expansion of apps and categories on the service, including the introduction of music services where users can share what they are listening to with friends.
The Open Graph Protocol enables you to integrate your Web pages into the social graph. It is currently designed for Web pages representing profiles of real-world things — things like movies, sports teams, celebrities, and restaurants. Including Open Graph tags on your Web page, makes your page equivalent to a Facebook Page. This means when a user clicks a Like button on your page, a connection is made between your page and the user. Your page will appear in the "Likes and Interests" section of the user's profile, and you have the ability to publish updates to the user. Your page will show up in the same places that Facebook pages show up around the site (e.g. search), and you can target ads to people who like your content. The structured data you provide via the Open Graph Protocol defines how your page will be represented on Facebook.
There is much more than what the current page shows: http://developers.facebook.com/docs/opengraph/
Zynga, Spotify etc use Open Graph, with frictionless integration, Serendipity and finding patterns of your friends.Instead of just Like or Recomment, it can be eat, listening etc.
Bret Taylor, Facebook's CTO, explained at F8 how the Open Graph can be integrated with your apps.