Squid.OAuth2 (nuget): Allows you to perform user authentication via DigitalOcean, Facebook, Foursquare, GitHub, Google, Instagram, LinkedIn, MailRu, Odnoklassniki, Salesforce, Twitter, VK (Vkontakte), Windows Live, Yandex just in two method calls.
Keywords: OAuth2|OAuth|DigitalOcean|Facebook|Foursquare|GitHub|Google|Instagram|LinkedIn|MailRu|Odnoklassniki|Twitter|VK|(Vkontakte)|Windows|Live|Yandex