You may want to look into OpenNIC, in which anyone with the know-how can operate a TLD.

They have domains like .geek, .cyb, .null, .libre, .oss, and you use them by simply switching your DNS server to one of OpenNIC's mirrors. They also support TLDs for "emerging nations" like .ku for Kurdish people, .uu for Uigurs, .ti for Tibet.

Though I'm not sure what would happen if ICANN decides to sell one of those domains one day.