CAS is probably the most used open access manager, let's spice it with SAML 2.0.
Small example on how to federate OpenAM with Wordpress via SAML 2.0.
Federations in MS SQL Azure are a way to achieve greater scalability and performance from the database tier of your application through horizontal partitioning. One or more tables within a database are split by row and portioned across multiple databases (Federation members).