Whoisology - Connected database of whois records and whois history
WhoisThisDomain - Domain name lookup tool that allows you to get information about domain registration from WHOIS server.
JsonWhois.io - JsonWhois is the leading cloud hosted Whois API.
JSON WHOIS API - Parsed domain WHOIS data from any WHOIS server via RESTful API with metered pay as you pricing.
WhoisAPI - WhoisAPI is the premier provider of freshly parsed whois data for domain names and IP addresses...
Active Whois Browser - Browse all information for an IP address or domain name with a single click!