Ruby Babel is a bridge to the JS Babel transpiler.

require 'babel/transpiler'
Babel::Transpiler.transform File.read("foo.es6")

$ gem install babel-transpiler

This library depends on the babel-source gem which is updated any time a new version of Babel is released.

The ExecJS library is used to automatically choose the best JavaScript engine for your platform. Check out its README for a complete list of supported engines.