The current ARPA-Internet hosts.
This domain name arose from the historic development of the Internet, and its predecessor ARPANET. The use of ARPA as a Top Level Domain was only temporary, until its hosts selected some other domain.
This domain was originally intended for any kind of government office or agency. More recently a decision was taken to register only agencies of the US Federal government in this domain. State and local agencies are registered in the country domains, which were developed in the 1990s.
This domain was originally intended for all educational institutions. Many Universities, colleges, schools, educational service organizations, and educational consortia have registered here.
This domain is intended for commercial entities, that is companies. This domain has grown very large and there is concern about the administrative load and system performance if the current growth pattern is continued.
This domain is used by the US military.
This domain is intended as the miscellaneous TLD for organizations that didn't fit anywhere else. Some non- government organizations may fit here.