Facebook Integration?

CNN allows you to login with your Facebook information, allowing for integrated distribution of content via Facebook.

So far, I’ve only seen this feature on CNN. Is this a Facebook open-source app? Or does Facebook have an exclusive relationship with CNN?

If it’s open source, how do I use it for my blog and commenting? Can I offer users the choice of using Facebook on top of regular registration? (There are security nuts out there, and I’m one of them.)

Thanks so much!