My article entitled "Single Sign-On with SAML on Force.com" is now available on the developerforce wiki.
"Implementing a Single Sign-On (SSO) infrastructure enables users to sign in once and have access to all authorized resources. In this article, we'll look at the different methods of implementing SSO with Force.com, how to set up your own open source identity management system for federated authentication using SAML 2, and how to configure the Force.com platform to utilize your new identify provider. We'll also provide some troubleshooting techniques and outline some best practices to help you avoid common roadblocks, getting you up and running fast..."
Read the entire article on the developerforce wiki...
