Install
With Bundler
gem 'unite'
Without Bundler
gem install unite
It's Science

Based on the algorithms developed by Gordon S. Novak, Jr. at the University of Texas, which can be found here:
http://www.cs.utexas.edu/users/novak/units95.html
Dimensions
Handles the following dimensions:
[:length, :time, :temperature, :mass, :current, :substance, :luminosity]
Can use Unite::Quantity to represent values or include the functionality into your own objects.
Look at https://github.com/stellard/unite/blob/master/lib/unite/quantity.rb for a minum implementation
Examples:
TODO: Needs more info here.
Unite::Quantity.init("1000*km")
Unite::Quantity.init("1000","km")
Unit definitions are found here:
https://github.com/stellard/unite/blob/master/lib/unite/lookup/definitions.rb
Specs show good examples of use.