We are beginning to tackle membership implementation on a new project and were researching available options. We were leaning toward .NET SimpleMembership until we found out that it must be configured with a direct link to your membership database(s). This didn’t sit well with us as it didn’t seem to fit with the repository and dependency injection models we are implementing. In our search for more information we stumbled upon Mr. Allen’s fantastic critique of the .NET Membership Provider model as well as his own open source membership solution utilizing Windows Identity Foundation. His blog post covers in detail many of the SimpleMembership short-comings we were seeing as well as several others we hadn’t yet encountered.