Amazon Route 53 - Amazon Route 53 is a highly available and scalable DNS web service.
Nuage - Nuage provides domain naming services.
GoDaddy DNS - GoDaddy DNS helps manage website performance, reliability and security.
Brandpa - Domain names for startups
NSONE - NSONE is a high performance DNS service providing unparalleled control over where end users are routed.
DomainWatch - Domain Monitoring Made Easy