Top 20 NuGet oauth Packages

ASP.NET Core security middleware enabling Battle.net authentication.
ASP.NET Core security middleware enabling Autodesk authentication.
ASP.NET Core security middleware enabling Odnoklassniki authentication.
TheIdServer administration application pages.
TheIdServer administration application components.
Operations and data types used with the ArcGIS REST API.
Authentication and service implementation for the Instagram API.
Provides an HttpClient DelegatingHandler for OAuth 2.0 / OpenID Connect authentication. This can also be used independently of the other TypedRest packages.
Reddit.NET is a .NET Standard library that provides easy access to the Reddit API with virtually no boilerplate code required.
IPWorks is a comprehensive framework of easy-to-use components for Internet development, including FTP, HTTP, SMTP, POP, IMAP, LDAP, DNS, SMS, SOAP, etc.
A cross-platform API for authenticating users and storing their accounts.
A netstandard2.0 library that consumes the new Instagram Basic Display API. Also includes a Razor Pages Web example that shows how to use the library and a Static site example that shows how to consume the new Instagram Basic Display API with just vanilla JavaScript.
ASP.NET Core security middleware enabling SuperOffice authentication.
SSO V2 KemenkeuID Client Library for .Net Standard
ASP.NET Server Side Library for The Identity Hub. The Identity Hub makes it easy to connect your app to all major identity providers like Microsoft, Facebook, Google, Twitter, Linked In and more. For more information see https://www.theidentityhub.com
OAuth Token Client Library.
Skybrud.Social is a framework in .NET for integration with various social services like Twitter, Facebook and Instagram. The framework will handle all the technical parts and API communication so you don't have to.
Latest version is part of InTheHand.Pontoon package. WebAuthenticationBroker for Windows Phone Silverlight 8.x apps. Share more code across platforms. Build Charming apps for Windows Phone!
An implementation of OAuth 1.0a for .NET Core based on Daniel Crenna's vaulted OAuth library
ASP.NET Core security middleware enabling Baidu authentication.