idn-mihu

https://github.com/mihu/idn

Ruby Bindings for the GNU LibIDN library, an implementation of the Stringprep, Punycode and IDNA specifications defined by the IETF Internationalized Domain Names (IDN) working group. Included are the most important parts of the Stringprep, Punycode and IDNA APIs like performing Stringprep processings, encoding to and decoding from Punycode strings and converting entire domain names to and from the ACE encoded form.