Kroman is ultimate Korean hangul romanization tool. It has a lot of implementations.
This is the Command line tool.
On OS X, you can install kroman with brew
brew tap cheunghy/kroman
brew install kroman
You may download the source code and make it. No dependencies are needed.
make install
kroman < nice_korean_song.txt > nice_singable.txt
Before:
희망은 잠들지 않는 꿈
After:
heui-mang-eun jam-deur-ji anh-neun ggum
Bug reports and pull requests are welcome on Github at https://github.com/cheunghy/kroman.
Kroman is available as open source under the terms of the MIT License.