> Linux is full of "almost does the job" alternatives, as exemplified in [2]. So is Windows. For example, you mentioned Kerberos. Only the Windows implementati

> Linux is full of "almost does the job" alternatives, as exemplified in [2]. So is Windows. For example, you mentioned Kerberos. Only the Windows implementation is so limited, that you can authenticate against one realm only. What if you need tickets from more realms? In Windows, tough luck. And no, you cannot replace the Windows Kerberos implementation with another security provider.