Passport Authentication .NET 3.5?

Guys!

What happened to Passport Authentication .NET Framework 3.5? Then MSDN for .NET Framework 3.5,
http://msdn.microsoft.com/en-us/library/eeyk640h.aspx
describes only about,
Windows Authentication Provider
Forms Authentication Provider

whereas MSDN for .NET Framework 3.0,
http://msdn.microsoft.com/en-us/library/eeyk640h(VS.85).aspx
describes only about,
Windows Authentication Provider
Forms Authentication Provider
Passport Authentication Provider

Is Passport Authentication Provider a legacy technology?

Please answer.  
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