1)   AddInternet Domain Search 1.33
AddInternet Domain Search is a free software that allows you to search for domain names available for registration as well as find out who is a domain owner by searching the global Whois database.

 2)   DomaiNIC 1.32
DomaiNIC is a speedy tool designed to generate and find good domain names easily. The smart fully customizable Domain Name Generator and the Domain Name Research Tool helps you in finding domain names that might yet be available.

 3)   KFWhois 2.4
KF Whois makes it easy to look up and store domain registration details. It tracks changes to domain registrations and warns you when they are about to expire.