Mapreduce is a project mainly written in Ruby, it's free.
Stuff for my independent study
First change the ip in ringserver.rb, worker.rb, and map_reduce_task.rb
Then in sperate terminals run 'ruby ringserver.rb', 'ruby worker.rb' (you'll need two of these), and 'ruby my_test.rb'
To change the map or reduce functions, edit the my_test.rb file