Get started with OpenID, OAuth and InfoCards today!

DotNetOpenAuth is a well established open source library that bring OpenID, OAuth, and ICard capabilities to the Microsoft .NET Framework.

Features

• Compiled library that adds support for your site visitors to login with their OpenIDs by just dropping an ASP.NET control onto your page. It’s that easy. An AJAX-style OpenID Selector control is also included for a slick, streamlined user experience.
• Give your site members their own OpenIDs with the provider support included in this library.
• Sample relying party and provider web sites show you just how to do it.
• Easy access to all the functionality so you can customize how OpenID will operate on your site, whether you use ASP.NET or not.
• Classic ASP support
• Full support for custom extensions. Plus built-in support for Simple Registration, Attribute Exchange and PAPE.
• Works in partial trusted shared hosting environments.
• Support for web farms where state persistence, front-facing web servers and ASP.NET may not be standard or even available.
• OpenID 2.0 and 1.x
• OAuth 1.0 and 1.0a
• Superior support for multi-byte Unicode identifiers.
• Lots of security features
• 490+ unit tests to verify correctness.
• Library behind the OSIS OpenID interop testing
• About 1500 downloads per month. See who’s using DotNetOpenAuth