This library presents whois information for domains in a variety of TLD's through a standardized API.
Gem for accessing the Whois XML API via JSON, with caching
Hexillion WhoIs API Client for Ruby
A simplistic interface to the ARIN whois database, similar to the API provided by Perl's Net::Whois::ARIN.
This gem contains class DeviantClient which helps use some Deviantart OAuth 2.0 API (load file to sta.sh, take user whois etc)
Ruby wrapper for Prompt API's Whois API
A Ruby SDK enables user to easily implement the checking of WHOIS information for a particular domain into their solution using the API from www.ip2whois.com
IP2Location.IO Ruby SDK allows user to query for an enriched data set based on IP address and provides WHOIS lookup api that helps users to obtain domain information.
Using the MetricsBot API, you can fetch free Domain Metrics, Whois Information and Domain Ranking API