Uconv

In computing, uconv is a command-line tool that is bundled with International Components for Unicode that converts text files between different character encodings. It is very similar to the "iconv" command that is part of the Single UNIX Specification which is usually implemented using libiconv. In fact the command line options for transliteration are the same. The command "uconv" can also convert to and from various Unicode normalization forms. 
There is also an alternative implementation written in Ruby. It was written to supplement support of Japanese encoding in Ruby's XML Parser.