Open Source .Net Authentication Libraries?

Question

I'm building a website and I'd like to avoid using asp.net membership. I want to consider some alternatives before I decide to write this code from scratch. Are there any open source projects that tackle the authentication problem?

note: I need user/pass auth (can't use Open Id).

Answer 1

Rhino Security is an option and there are some articles on how to integrate it with ASP.NET MVC as well.