Freenom and Dot TK are two companies that offer free domain registration on their websites as of 2015. Award Space also offers free domain registration but restricts the service to paid members of its website.
Freenom provides both free and paid domain name registration. While free domain name registration is the standard method, paid users gain the legal license rights to the domain names. Legal license rights allow clients to register the domain names for extended periods of time and allows them to sell and transfer the domains. Dot TK allows users to register free domain names ending in ".tk."