List all tasks from your custom rake file

namespace :my_application do |ns|
  desc "Lists all tasks available"
  task :tasklist do
    ns.tasks.each do |t|
      name   = t.name_with_args
      spaces = name.length >= 25 ? "\t" : "\t\t" # hack for spacing
      puts name + spaces + t.comment.to_s
    end
  end
end