Whois - Version 2.9.3 Whois Tool is a client utility that communicates with WHOIS servers located around the world to obtain domain registration information. Whois supports IP address queries and automatically selects the appropriate whois server for IP addresses. This tool will lookup information on a domain, IP address, or a domain registration information. Whois Tool is a client utility that communicates with WHOIS servers located around the world to obtain domain registration information. Whois supports IP address queries and automatically selects the appropriate whois server for IP addresses.