Open source License that doesn't require credit

Is there a known open-source license where the user who reuses or redistributes the code is not required to give credit to the author? This is actually the same as just assuming copyright to the collection but placing the contents on the public domain.

P.S.

For me that is the real "open" and real "free" software, for not only everyone that uses it but also everyone that reads it and contributes to it is not bound to and is free in mind from any conditions that could prevent from them doing anything on the software (including parts of software that already resides within their brains) . No forced or not-so-obvious or tempted viral injection of philosophies.