See a recent posting by OpenSSO engineer Giuseppe Gennaro on the .NET Fedlet, which enables federation among .NET applications through Security Assertion Markup Language (SAML) 2.0. The posting refers to a prototype created by Sun identity architect Rajeev Angal and contains steps for trying things out.

Also see Sun senior product line manager Daniel Raskin's posting on this subject: "The Fedlet is truly light and requires no hardware, maintenance, upgrades, or license." Impressive!