We're gonna write a pair of programs that convert Roman numerals to their Arabic counterparts and vice versa.

> ./deromanize I
1
> ./deromanize II
2
> ./deromanize MCMIV
1904

> ./romanize 1
I
> ./romanize 2
II
> ./romanize 1904
MCMIV

My advice is to start with the deromanize part. To start:

1. Create a directory based on the name of your implementation language (e.g. languages/C)
2. Create a simple Rakefile that has, at a minimum, a build task within your language's namespace (e.g. C:build). You should check the environment and fail fast if dependencies aren't met.
3. Create your implementation and run rake from the project root.

namespace :C do
  task :check do
    `which cc`
    raise "Please ensure that you have a valid C compiler" unless $?.success?
  end

  task :build => :check do
    path = File.dirname(__FILE__)
    `cd #{path}; make romanize`
  end
end