Wikipedia
.xxx
.xxx (pronounced "dot triple- ecks" or "dot ecks ecks ecks") is a sponsored top-level domain (sTLD) intended as a voluntary option for pornographic sites on the Internet. The sponsoring organization is the International Foundation for Online Responsibility (IFFOR). The registry is operated by ICM Registry LLC. The ICANN Board voted to approve the sTLD on 18 March 2011. It went into operation on 15 April 2011.
The TLD entered its sunrise period on 7 September 2011 at 16:00 UTC; the sunrise period ended 28 October 2011. Landrush period lasted from 8 November through 25 November, and General Availability commenced on 6 December 2011.