IsHostedBy.com - IsHostedBy is a website where you can lookup where certain websites are hosted.
Whoisology - Connected database of whois records and whois history
CubDomain - CubDomain.com is the site to check website's statistics, Information, Whois Record, Hosting...
WebCargo - Optimize your workflow by offloading it to us. Useful API's with seamless integration that scale to your needs.
DNS Checker Tool - Check Domain Name System (DNS) records for any website.
WhoisThisDomain - Domain name lookup tool that allows you to get information about domain registration from WHOIS server.