DotNetOpenAuth 是***使用的库，它是OpenID和OAuth。它是免费的，开源的，你自己承担（不需要第三方）。

DotNetOpenAuth is the library *** uses, and it does OpenID and OAuth. It's free, open source and you host it all yourself (no 3rd-party required).

它的最新版本还没有包括Facebook（OAuth 2.0）支持，但会在下一个版本（几个星期之内）。

It's latest version doesn't yet include Facebook (OAuth 2.0) support but that will come in the next version (a few weeks away).