Download MS Windows Identity Foundation for free

This MS Identity Foundation helping simplified access
of users for developers via externalizing access of
users from the appilcation by decreasing development
effort and claims with built in security logic and
.Net tools(integrated).

user benefit are-
1.single sign on
2.collaboration across or in organizational boundaries
seamlessly.

download link & help-
msdn.microsoft.com/hi-in/evalcenter/dd440951.aspx