Best OpenId API for ASP.NET MVC application

Question

I am developing an ASP.NET MVC application and I want to use OpenId.

What is the best option?

Does anyone know what StackOverflow uses? Is the Login UI custom-developed, or provided by an API/service?

Jarrod_Dixon_3 · Answer

We use the excellent DotNetOpenId library here on Stack Overflow:

http://code.google.com/p/dotnetopenid/

now moved to:

http://www.dotnetopenauth.net/

Our original login UI was provided by ID Selector, but we've since rolled our own minimalist version.

John_Sheehan_1786 · Answer

I'll second the recommendation for DotNetOpenId and add a recommendation for openid-selector (open source version of idselector)