How do I implement Facebook Connect alongside OpenID on my website?

Right now I have a website that only accepts OpenIDs. Each user's account is associated with an OpenID identifier. How would I allow users to use Facebook Connect to login?

Are there an开发者_StackOverflow社区y free, open-source client authentication libraries that abstract away the task of dealing with multiple services? I'm not looking for a service like RPX.

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you can have a look at these two websites:

http://developers.facebook.com/docs/guides/web

http://mashable.com/2009/09/30/facebook-connect-wizard/