Whoisology - Connected database of whois records and whois history
WhoisAPI - WhoisAPI is the premier provider of freshly parsed whois data for domain names and IP addresses...
Bulk Whois API - Bulk Whois API is a provider of parsed WHOIS data in JSON with simple API, competitive pricing, top notch support, and more.
Whois.net - Whois lookup for domain name search, registration and availability.
WhoisThisDomain - Domain name lookup tool that allows you to get information about domain registration from WHOIS server.
Oribi - Analytics for marketing & product teams