WHOIS++

Classic whois was a single database run by a central registrar. Peter Deutsch of Bunyip — one of the people behind Archie — and his co-authors described a successor in RFC 1835 in which every organisation ran its own server, with structured templates for people, services and hosts. The protocol was assigned port 63.

The clever part was centroids: each server sent a summary of the words appearing in its records up to index servers, so a query could be routed to the right place without anyone holding the entire directory. The competition was stiff, though. X.500 had the institutions, CSO had the campuses, and in the end LDAP won inside companies while nobody got the global directory at all.