The following are some of the important organisations in the domain name industry.
ARIN
American Registry for Internet Numbers is a a not for profit organisation established to handle the administration and registration of Internet Protocol (IP) addresses in North America, some of the Caribbean, and sub-Saharan Africa.
CORE Internet Council of Registrars is a not for profit organisation set up under Swiss law. Core is made up of domain name registrars handling domain name registration on behalf of customers.
IANA
Internet Assigned Numbers Authority is the authority given the initial responsibility for the oversight of IP address allocation, the coordination of the assignment of protocol parameters provided for in Internet technical standards, and the management of the DNS.
ICAAN
Internet Corporation for Assigned Names and Numbers is an internationally organized, non-profit corporation that has responsibility for Internet Protocol (IP) address space allocation, protocol identifier assignment, generic (gTLD) and country code (ccTLD) Top-Level Domain name system management, and root server system management functions.
IETF
Internet Engineering Task Force is an open international community of network designers, operators, resellers, and researchers concerned with the evolution of the Internet architecture and the operation of the Internet. Membership is open to any interested individual or corporation.
Nominet Nominet is the UK TLD registrar responsible for the management and development of the .uk domain range.
W3C
World Wide Web Consortium is an international industry consortium set up to develop common protocols to promote the evolution of the World Wide Web and ensure its smooth operation. Services include; a repository of information about the World Wide Web for developers and users; reference code implementations to promote standards; and various prototype and sample applications to demonstrate use of new technology.