Ars Technica has an article on Microsoft's recent moves to secure and strengthen interoperability in web identity management frameworks. As the article avers:

The concept of web identity involves three participants: the user/customer, the web site owner, and a third party that holds information that can verify the user's identity. The services and projects Microsoft has announced are intended to improve interoperability between all three components of a web-based identity system.

Read the article in full here .