Google to launch OpenSocial social networking project

OpenSocial is a set of three common APIs, defined by Google with input from partners, that allow developers to access core functions and information at social networks:

• Profile Information (user data)
• Friends Information (social graph)
• Activities (things that happen, News Feed type stuff)

Hosts agree to accept the API calls and return appropriate data. Google won’t try to provide universal API coverage for special use cases, instead focusing on the most common uses. Specialized functions/data can be accessed from the hosts directly via their own APIs.

Unlike Facebook, OpenSocial does not have its own markup language (Facebook requires use of FBML for security reasons, but it also makes code unusable outside of Facebook). Instead, developers use normal javascript and html (and can embed Flash elements). The benefit of the Google approach is that developers can use much of their existing front end code and simply tailor it slightly for OpenSocial, so creating applications is even easier than on Facebook.

Applications can have full functionality on profile and/or canvas pages, subject to the specific rules of each host. Facebook, by contrast, limits most functionality to the canvas page, allowing a widget on the profile page with limited features.

OpenSocial is silent when it comes to specific rules and policies of the hosts, like whether or not advertising is accepted or whether any developer can get in without applying first (the Facebook approach). Hosts set and enforce their own policies. The APIs are created with maximum flexibility.