p RUBY_ENGINE
# => "rbx"

Rubinius is a Ruby interpreter that translates Ruby to LLVM bytecode, and then to native machine code. Rubinius also implements most of the core library in Ruby. It also has its 'actor' library.

Rubinius 1.2.x only implements Ruby 1.8.7, it cannot run Ruby 1.9 code.

• http://rubini.us/