Lean Domain Search - Find a Great Domain Name w/ twitter handle availability
WhoisThisDomain - Domain name lookup tool that allows you to get information about domain registration from WHOIS server.
Brandpa - Domain names for startups
WebCargo - Optimize your workflow by offloading it to us. Useful API's with seamless integration that scale to your needs.
SafeSocial - Make the Internet a better place
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.