When generic top-level domains were first implemented, in January 1985, there were six:
While .net was not listed in the original RFC document describing the domain name system, it was added by the time the first group of names were implemented.
The .com, .net, and .org gTLDs, despite their original different uses, are now in practice open for use by anybody for any purpose.
In November 1988, another gTLD was introduced, .int. This gTLD was introduced in response to NATO’s request for a domain name which adequately reflected its character as an international organization. It was also originally planned to be used for some Internet infrastructure databases, such as .ip6.int, the IPv6 equivalent of .in-addr.arpa. However, in May 2000, the Internet Architecture Board proposed to close the .int domain to new infrastructure databases. All future such databases would be created in .arpa (a legacy of the pre-TLD system), and existing ones would move to .arpa wherever feasible, which led to the use of .ip6.arpa for IPv6 reverse lookups.
By the mid-1990s there was pressure for more gTLDs to be introduced. Jon Postel, as head of IANA, invited applications from interested parties. In early 1995, Postel created “Draft Postel”, an Internet draft containing the procedures to create new domain name registries and new TLDs. Draft Postel created a number of small committees to approve the new TLDs. Because of the increasing interest, a number of large organizations took over the process under the Internet Society’s umbrella. This second attempt involved the setting up of a temporary organization called the International Ad Hoc Committee (IAHC). On February 4, 1997, the IAHC issued a report ignoring the Draft Postel recommendations and instead recommended the introduction of seven new gTLDs (.arts, .firm, .info, .nom, .rec, .store, and .web). However, progress on this stalled after the U.S. government intervened and nothing ever came of it.
In October 1998, the Internet Corporation for Assigned Names and Numbers (ICANN) formed to take over the task of managing domain names. After a call for proposals (August 15, 2000) and a brief period of public consultation, ICANN announced on November 16, 2000 its selection of the following seven new gTLDs:
These new gTLDs started to come into use in June 2001, and by the end of that year all except .pro existed, with .biz, .info and .museum already in full operation. .name and .coop became fully operational in January 2002, and .aero followed later in the year. .pro became a gTLD in May 2002, but did not become fully operational until June 2004.
ICANN is adding further gTLDs, starting with a set of sponsored top-level domains (like the previous .aero, .coop, and .museum). The application period for these lasted from 15 December 2003 until 16 March 2004, and resulted in ten applications. As of June 2005, ICANN had announced the approval in principle of several new TLDs, with details still being worked out and implementation still in the future:
- .cat (now live)
- .jobs (now live)
- .mobi (now live)
- .travel (now live)
- .xxx (approval revoked by ICANN)
Proposals for .mail were still under consideration. There was also a second proposal for .tel.