New.net

Website of one of the leading alternate roots. Includes a download of a plug-in that will allow users to utilize the alternate roots provided. The website also includes registration services.
http://www.new.net

IPv8 G:S Numbers and TLDs

Listing of proposed alternate TLDs in the 128-bit DNS supported by IPv8. These TLDs are NOT supported by ICANN.
http://www.ntia.doc.gov/ntiahome/domainname/130dftmail/unir.txt

Dot-Web

Registration for the .WEB TLD.
https://www.webtld.com/

Domain Name Systems

Alternate Registry of the .xxx and .sex domains.
http://www.domainnamesystems.com

OpenNIC

Completely open and democratically managed root domainname system.
http://www.opennic.unrated.net/

AGN Domain Name Services

Registration of alternative .earth, .usa, and .z top level domains.
http://www.adns.net/

Generic Universal NameSpace - .www

The Generic Universal NameSpace (GUNS) is an alternative to the Legacy namespace and uses the top level domain (tld) "www" as its root. Domain registrations under www resolve using an inclusive (alternate) namespace root.
http://www-tld.com

Mobile Domain Names Registrar

MobileTLD.com registers domain names for Wireless Internet use in 9 zones (.mobile, .imode, .mmode, .palm, .wap, .hdml, .3g, .wire, .pda) and 340 second level spaces.
http://www.mobiletld.com