In the 1980s, seven gTLDs (.com, .edu, .gov, .int, .mil, .net, and .org) were created. Domain names may be registered in three of these (.com, .net, and .org) without restriction; the other four have limited purposes.
In years following the creation of the original gTLDs, various discussions occurred concerning additional gTLDs, leading to the selection in November 2000 of seven new TLDs for introduction. These were introduced in 2001 and 2002. Four of the new TLDs (.biz, .info, .name, and .pro) are unsponsored. The other three new TLDs (.aero, .coop, and .museum) are sponsored. In 2003, ICANN initiated a process that resulted in the introduction of six new TLDs (.asia, .cat, .jobs, .mobi, .tel and .travel) that are sponsored. Information about that process may be found here.
Generally speaking, an unsponsored TLD operates under policies established by the global Internet community directly through the ICANN process, while a sponsored TLD is a specialized TLD that has a sponsor representing the narrower community that is most affected by the TLD. The sponsor thus carries out delegated policy-formulation responsibilities over many matters concerning the TLD.
A Sponsor is an organization to which is delegated some defined ongoing policy-formulation authority regarding the manner in which a particular sponsored TLD is operated. The sponsored TLD has a Charter, which defines the purpose for which the sponsored TLD has been created and will be operated. The Sponsor is responsible for developing policies on the delegated topics so that the TLD is operated for the benefit of a defined group of stakeholders, known as the Sponsored TLD Community, that are most directly interested in the operation of the TLD. The Sponsor also is responsible for selecting the registry operator and to varying degrees for establishing the roles played by registrars and their relationship with the registry operator. The Sponsor must exercise its delegated authority according to fairness standards and in a manner that is representative of the Sponsored TLD Community.
The extent to which policy-formulation responsibilities are appropriately delegated to a Sponsor depends upon the characteristics of the organization that may make such delegation appropriate. These characteristics may include the mechanisms the organization uses to formulate policies, its mission, its guarantees of independence from the registry operator and registrars, who will be permitted to participate in the Sponsor's policy-development efforts and in what way, and the Sponsor's degree and type of accountability to the Sponsored TLD Community.