This C# OpenID library adds OpenID 2.0 Provider and Relying Party support to your web site both programmatically and through convenient drop-in ASP.NET controls.
Features
Add 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 login 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. New CTP showing off 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 support.
Superior support for multi-byte Unicode identifiers.
Lots of Security features
250+ unit tests to verify correctness.
项目主页：http://code.google.com/p/dotnetopenid/
下载地址：http://code.google.com/p/dotnetopenid/downloads/list
来自:开源中国社区
