Ruby Markdown Benchmarks from http://tomayko.com/writings/ruby-markdown-libraries-real-cheap-for-you-two-for-price-of-one

benchmark.rb

iterations = 100
test_file = "#{File.dirname(__FILE__)}/benchmark.md"
implementations = [
  {class_name: 'BlueCloth', gem_name: 'bluecloth', require_name: 'bluecloth'},
  {class_name: 'RDiscount', gem_name: 'rdiscount', require_name: 'rdiscount'},
  {class_name: 'Maruku', gem_name: 'maruku', require_name: 'maruku'},
  {class_name: 'PEGMarkdown', gem_name: 'rpeg-markdown', require_name: 'peg_markdown'},
]

# Attempt to require each implementation and remove any that are not
# installed.
implementations.reject! do |implementation|
  begin
    require implementation[:require_name]
    false
  rescue LoadError => boom
    puts "#{class_name} excluded. Try: gem install #{implementation[:gem_name]}"
    true
  end
end

# Grab actual class objects.
implementations.map! { |implementation| Object.const_get(implementation[:class_name]) }

def benchmark(implementation, text, iterations)
  start = Time.now
  iterations.times do |i|
    implementation.new(text).to_html
  end
  Time.now - start
end

test_data = File.read(test_file)

puts "Spinning up ..."
implementations.each { |impl| benchmark(impl, test_data, 1) }

puts "Running benchmarks ..."
results =
  implementations.inject([]) do |r,impl|
    GC.start
    r << [ impl, benchmark(impl, test_data, iterations) ]
  end

puts "Results for #{iterations} iterations:"
results.each do |impl,time|
  printf "  %10s %09.06fs total time, %09.06fs average\n",
    "#{impl}:", time, time / iterations
end