SocialAuth.NET - OAuth with Facebook, Yahoo, Google, Twitter & more

So last time when you visited your favourite site, you were pleased to see that it allowed login through facebook also besides direct registration . This is such a convenient functionality as user tend to be lazy to fill in registration forms and then wait for email with activation link. If you are looking for implementing similar functionality in your application then you can simply use "Facebook Button" from Facebook. But what if you want to implement authentication with Yahoo, Google and MSN as well?
Well there is an out of the blue easy solution to achieve it! Meet SocialAuth.NET.

SocialAuth.NET is a .NET class library that can be used to implement authentication with Facebook, Yahoo, Google and MSN. Using this library is so easy, that even if you are aware of writing simple application with ASP.NET, you can easily use this library.

This library provides following features:
- Authentication with Yahoo, Google, Facebook, MSN, Twitter, LinkedIn, MySpace
- Retrieval of user profile
- Retrieval of user friends
- Automatic authentication engine
- Option for generating custom provider selection UI with simple HTML or .NET controls
- Framework for extending this API for other providers like Foursquare etc. .
- Easily switch authentication mechanism between OAuth1a, Hybrid and Oauth2
- Execute REST APIs on supported provider and build your applications
- Persist tokens and restore them later
- Integrate library  in less than 15 minutes

CodeProject