Rubikon is a simple to use, yet powerful Ruby framework for building console-based applications. Rubikon aims to provide an easy to write and easy to read domain-specific language (DSL) to speed up development of command-line applications. With Rubikon it's a breeze to implement applications with only few options as well as more complex programs like RubyGems, Homebrew or even Git.


You can install Rubikon using RubyGems. This is the easiest way of installing and recommended for most users.

$ gem install rubikon

If you want to use the development code you should clone the Git repository:

$ git clone git://
$ cd rubikon
$ rake install


Creating a Rubikon application is as simple as creating a Ruby class:

require 'rubygems'
require 'rubikon'

class MyApplication < Rubikon::Application::Base

If you save this code in a file called myapp.rb you can run it using ruby myapp.rb. Or you could even add a shebang (#!/usr/bin/env ruby) to the top of the file and make it executable. You would then be able to run it even more easily by typing ./myapp.rb.

Now go on and define what your application should do when the user runs it. This is done using default:

class MyApplication < Rubikon::Application::Base

  default do
    puts 'Hello World!'


If you run this application it will just print Hello World!.

You can also add command-line options to your application using command:

class MyApplication < Rubikon::Application::Base

  command :hello do
    puts 'Hello World!'


This way your application would do nothing when called without options, but it would print Hello World! when called using ruby myapp.rb hello. A command is code that is executed when the application is called with the command's name as the first argument - just like RubyGem's install or Git's commit.

Another part of Rubikon's DSL are flags and options. Both are parameter types that change the behaviour of the application. While a flag is a parameter without arguments, an option may take one or more additional arguments. Typical examples for flags are --debug or --verbose (or short -d and -v). RubyGem's --version is an example for an option that requires additional arguments. Flags and options are easily added to your application's commands using Rubikon's DSL:

flag :more, 'A flag'
option :name, 'An option', :who
command :hello, 'A command' do
  puts "Hello #{who}"

Please see the Wiki for more information on the DSL or the samples directory for more in detail sample applications.


Rubikon is still in an early development stage. If you want to use it be aware that you will might run into problems and or restrictions. See the Contribute section if you want to help to make Rubikon better.


  • A simple to use DSL
  • Automatic checks for option arguments
  • Built-in methods to capture user input
  • Built-in methods to display progress bars and throbbers
  • Built-in support for configuration files
  • Built-in support for colored output
  • Automatic generation of application and command help screens
  • User defined validation of option arguments

Future plans

  • Improved error handling
  • General optimizations
  • Improved tests


  • Linux, MacOS X or Windows
  • Ruby 1.8.6 or newer (see the compatibility page in Rubikon's wiki)


Rubikon is a open-source project. Therefore you are free to help improving it. There are several ways of contributing to Rubikon's development:

  • Build apps using it and spread the word.
  • Report problems and request features using the issue tracker.
  • Write patches yourself to fix bugs and implement new functionality.
  • Create a Rubikon fork on GitHub and start hacking. Extra points for using GitHubs pull requests and feature branches.

About the name

Rubikon is the German name of the river Rubicone in Italy. It had a historical relevance in ancient Rome when Julius Caesar crossed that river with his army and thereby declared war to the Roman senate. The phrase "to cross the Rubicon" originates from this event.

You may also see Rubikon as a portmanteau word consisting of "Ruby" and "console".


This code is free software; you can redistribute it and/or modify it under the terms of the new BSD License. A copy of this license can be found in the LICENSE file.


  • Sebastian Staudt -- koraktor(at)
  • Dotan J. Nahum -- jondotan(at)

See Also

Follow Rubikon on Twitter @rubikonrb.