Microsoft made available codename “Geneva” on the Microsoft Download Center. The November 25 release is designed to support not only Windows Vista RTM/SP1 and Windows Server 2008 RTM/SP1, but also Windows 7.
According to the Redmond company, Geneva is an open platform, designed to streamline user access, while relying on claims. In this context, Geneva is intimately connected with the Windows CardSpace identity technology from Microsoft, in the sense that it can be used to either use CardSpace for access, or in the absence of CardSpace, it can implement claims-based access, with claims being capable of delivering a variety of information.
More info: Microsoft Download Center