Domainz.io - Premium domains, for not so premium prices
PowerDNS - PowerDNS offers open source DNS software, services, and support.
Brandpa - Domain names for startups
dnsmasq - Dnsmasq is a lightweight, easy to configure DNS forwarder and DHCP server.
Undeveloped - Domains you never thought were available
Unbound - Unbound is a validating, recursive, and caching DNS resolver.