.dj is the country code top-level domain (ccTLD) for Djibouti.
The domain has also been marketed as a domain hack for music-related sites due to the common use of "DJ" to mean disc jockey; examples include rave.dj, transitions.dj, and cord.dj.
See also
.am .cd .fm .me .mu
References
External links IANA .dj whois information
sv:Toppdomän#D