Fibonacci is a project mainly written in Ruby, based on the MIT license.
Gem for adding fibonacci awesomeness to fixnum
git clone git://github.com/sam1vp/fibonacci.git
cd fibonacci
gem build fibonacci.gemspec
gem install fibonacci-0.1.0
require 'fibonacci'
151.closest_fibonacci #=> 144, the first fibonacci number below your fixnum
Now go get your fibonacci on.