The mkpasswd utility is present on many Linux systems as part of the base install. In Ubuntu 12.04, for some unknown reason, it appears to be part of the "whois" package. Other than "historical reasons", is there a reason for this seemingly arbitrary inclusion?
According to Marco d’Itri in his answer to the same question in an issue ticket it is only because of historical reasons:
It was part of the original RIPE whois package which I packaged before writing my own implementation.