Whoisology - Connected database of whois records and whois history
Whats My DNS - Instantly check your domain names current IP address and DNS record information against multiple name servers located in different parts of the world.
CheckNameserver.com - Nameserver Checker Tools
ViewDNS.info - Free DNS related tools including Reverse IP Lookup, DNS Propagation Checker, Chinese Firewall Test...
WebCargo - Optimize your workflow by offloading it to us. Useful API's with seamless integration that scale to your needs.
CubDomain - CubDomain.com is the site to check website's statistics, Information, Whois Record, Hosting...