I write another one for ruby, check out samples here: https://github.com/quark-zju/easysh

Although its functions are a subset of sh for python. It has many synatactic sugars, makes full use of ruby Enumerable, and does lazy-execute.

Seems not working with cruby 1.9.3 ? SyntaxError: .../rubysh-0.0.2/lib/rubysh/subprocess/parallel_io.rb:77: Invalid next