Facebook Open Graph: Publisher Plugins

The Open Graph is a set combination of publisher plugins, semantic markup and a developer API.

Login with Faces & Facepile: The simpler publisher plugins enhance Facebook Connect. They makes it easy and compelling to sign in by leveraging Facebook cookies and showing faces of Facebook friends who are already members of the service.

Like Button and Like Box: These plugins add the liking feature to any content, typically the whole page. Both can be enhanced with semantic markup, described below. But the very basic intent for these is to get users to Like on the site and post a link to Facebook, which is then permanently stored on a user's profile and points back to the original site.

Activity Feed and Live Stream: These plugins show static and dynamic activity on the site. Activity Feed lists recent likes and comments from the site, while Live Stream shows a real-time view of activity on the site and is intended for interactive events.

Recommendations: This plugin surfaces personalized recommendations for the user based on what friends and everyone else is liking on the site. It is intended to drive the users to other pages on the site.

Facebook Open Graph: Semantic Markup

Facebook announced simple, RDF-based markup to make the plugins smarter. In a nutshell, the markup enables publishers to say what object is on the page - a movie, a book, a recording artist, an event, a sports team, etc. This automatically enables semantics, that is, an understanding that the user is not just interacting with a webpage, but that he or she is liking a specific kind of thing. Semantics then leads to bucketing of the objects into categories like books, movies, music, etc., and gives rise to all sort of applications, including personalized recommendations.

Perhaps even more importantly, the markup helps Facebook connect the users across common interests across different websites. For example, if both Pandora and Last.fm annotate a page about The Beatles using Facebook's markup, then users will be able to see their friends, who like the Beatles across different sites. This is very significant, because the data around friends is sparse and scattered around the sites. Previously, Facebook would surface this data in the stream without persisting it. Now, the information about a friend's likes of movies, music, books, recording artists, events, sports team, etc. will be permanent on Facebook profiles and readily available in context around the Web.

Facebook Open Graph: New API

The new Facebook API is elegant and streamlined. It makes it easy to access user information (with permission of course) such as profile, friends, etc. All of the calls are REST based and return JSON objects. For example, my profile information can be fetched like this: http://graph.facebook.com/alexiskold. The authentication is based on OAuth 2.0 protocol and makes it simple not only to connect, but to also prompt for permissions to access user information.

This new API turns Facebook into a read/write storage of users' tastes. And not just one user - all Facebook users.