Best way to enable sign in to my website using Facebook, Twitter, LinkedIn, Google, Yahoo, etc.?

We're creating a new website and we want to simplify the sign in process. I see that a lot of sites let you sign in through Facebook, Twitter, etc..

We're looking for something that is fast, simple to implement, and cheap.

What's the best way to do it?

I've come across http://janrain.com and http://www.gigya.com. Any comments on them?

Also, general comments on the wisdom of doing this at all are welcome. Are there any downsides? Our website is a SAAS B2B-oriented site which aims to take a complicated, expensive software product and 开发者_开发百科present it in a cheap, easy, and consumer-ish way.

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Most of the websites you mentioned supports OpenID or OAuth.

OpenID providers: http://openid.net/get-an-openid/

Google and Yahoo are OpenID providers. Google, Twitter, Facebook and LinkedIn supports OAuth as well.

Understanding this, it is your business decision to rollout your own implementation base on available libraries (there are enough libraries to this job I believe) of your technology, or use some third-party service like http://janrain.com or http://gigya.com.

For me, I will prefer to use my own implementation as there is one less dependency and I like to control authentication process myself.

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You might want to try the EmpowerID. It lets you federation your application with all the major identity providers including Facebook, Twitter, Salesforce, Yahoo, MSN Live etc. etc.