~/NetBeansProjects/jruby ➔ jruby --server chain_bench.rb 
Time per iteration = 93.34 microseconds
~/NetBeansProjects/jruby ➔ ruby chain_bench.rb 
Time per iteration = 700.36589 microseconds
~/NetBeansProjects/jruby ➔ ../ruby1.9/ruby chain_bench.rb 
Time per iteration = 152.15469 microseconds
~/NetBeansProjects/jruby ➔ ../rubinius/bin/rbx chain_bench.rb 
Time per iteration = 165.06361 microseconds