Google has added the OpenSocial API code to the web. OpenSocial provides a common set of APIs for social applications across multiple websites which enables developers can create apps that access a social network’s friends and update feeds. We suppose it allows you to travel from Linked In to Facebook to Likemind and still have the same log-in and data. Google explains how it wants to make the web more social:
Common APIs mean you have less to learn to build for multiple websites. OpenSocial is currently being developed by Google in conjunction with members of the web community. The ultimate goal is for any social website to be able to implement the APIs and host 3rd party social applications. There are many websites implementing OpenSocial, including Engage.com, Friendster, hi5, Hyves, imeem, LinkedIn, MySpace, Ning, Oracle, orkut, Plaxo, Salesforce.com, Six Apart, Tianji, Viadeo, and XING.
This video explains a little more: