If the crypto method being used is strong enough, then there is no need to obscure the authentication algorithm or the salted value. That just provides a little bit of security through obscurity, it doesn't actually harden the passwords anymore. Thus, modern password hashing libraries just put the algorithm and salt information in the password string itself, so that the string of data you store in the database contains 3 pieces of data: The algorithm used to hash the password, the salt, and the password hash. The benefit of this is convenience: Different platforms/languages can all create/authenticate various password hash types with ease as long as everybody sticks to this format.
And because of this, if you choose a weak crypto method to hash your passwords (which is what MtGox did), then an attacker conveniently has the 3 things they need to attempt to crack the password: The algorithm, the salt and the hashed value all in the same place.
However, if a strong crypto is used (IE a computationally intensive and slow hash), then the fact that the algorithm, salt and hashed value are in the same place doesn't really weaken the passwords. With an expensive enough hash, even if the attacker has all the information about how to crack the password right in front of them, actually performing the necessary computation would be so expensive that a brute force attack is effectively protected against.
You can see more details about the format of the password strings and where the 3 parts of data are stored here: http://php.net/manual/en/function.crypt.php
(the PHP page had the best explanation of my quick search, though this isn't just PHP specific)
And because of this, if you choose a weak crypto method to hash your passwords (which is what MtGox did), then an attacker conveniently has the 3 things they need to attempt to crack the password: The algorithm, the salt and the hashed value all in the same place.
However, if a strong crypto is used (IE a computationally intensive and slow hash), then the fact that the algorithm, salt and hashed value are in the same place doesn't really weaken the passwords. With an expensive enough hash, even if the attacker has all the information about how to crack the password right in front of them, actually performing the necessary computation would be so expensive that a brute force attack is effectively protected against.
You can see more details about the format of the password strings and where the 3 parts of data are stored here: http://php.net/manual/en/function.crypt.php (the PHP page had the best explanation of my quick search, though this isn't just PHP specific)