OpenSocial and Liberty People Services are really tackling the same problem – only from two opposing sites. While the LAP PS has established a solid foundation for secure identity management, OpenSocial has started out to define an API for allowing social networking (but also other) software from different source to be run in one (or more than one) container. Ideally, these container abstract away the underlying platform and thus enable application portability. This becomes quite useful, since facebook, MySpace, Orkut, etc. have extremely similar types of applications (friends/relationships, photo sharing, contact management, and many more). Having these applications being portable across different allows application developers to focus more on added functionality and less on platform plumbing.
Liberty – on the other hand – has created the necessary infrastructure to enable individuals to set preferences and share information about themselves with other in a secure and privacy preserving way. The protocols used in ID-WSF and people service (and not APIs) can enable containers to communicate with others based on user’s policies and requests.