The WHOIS++ protocol is a distributed directory system, originally designed to provide a "white pages" search mechanism to find humans, but which could actually be used for arbitrary information retrieval tasks. It was developed in the early 1990s by BUNYIP Information Systems and is documented in the IETF.

An Internet directory service for looking up names of people on a remote server. Many servers respond to TCP queries on port 43, in a manner roughly analogous to the DDN NIC whois service described in RFC 954. Other sites provide this directory service via the finger protocol or accept queries by electronic mail for directory information. On Unix the client command is whois -h server_name person_name You can also type "telnet server_name 43" and then type the person's name on a separate line. For a list of whois servers, FTP/Gopher: sipb.mit.edu. Or whois -h sipb.mit.edu whois-servers As the above command demonstrates, whois can find information about things other than users, e.g. domains, networks and hosts. See also finger, X.500, white pages.

WHOIS (pronounced as the phrase "who is") is a query and response protocol that is widely used for querying databases that store the registered users or assignees of an Internet resource, such as a domain name, an IP address block or an autonomous system, but is also used for a wider range of other information. The protocol stores and delivers database content in a human-readable format.