diff --git a/std-script/judge b/std-script/judge
new file mode 100755
--- /dev/null
+++ b/std-script/judge
@@ -0,0 +1,114 @@
+#!/usr/bin/ruby
+
+problem_home = ENV['PROBLEM_HOME']
+
+def execute(command, error_message="")
+  if not system(command)
+    puts "ERROR: #{error_message}"
+    exit(127)
+  end
+end
+
+# ARGV[0] --- language
+# ARGV[1] --- program source file
+# ARGV[2] --- test result directory
+# ARGV[3] --- sandbox directory
+
+if ARGV.length < 2 || ARGV.length > 4
+  puts "Usage: judge <language> <program-source> [<test-result-directory>] [<sandbox-directory>]"
+  puts "  <sandbox-directory> is defaulted to ./sandbox"
+  puts "  <test-result-directory> is defaulted to ./test-result"
+  puts "WARNING: The judge script will forcefully create the (implicitly and explicitly) specified directories and remove anything inside it."
+  exit(127)
+end
+
+language = ARGV[0]
+if language != "c" && language != "c++" && language != "pascal"
+  puts "You specified a language that is not supported."
+  exit(127)
+end
+
+source_file = ARGV[1]
+if File.exist?(source_file) == false
+  puts "The source file does not exist."
+  exit(127)
+end
+
+puts "Making test result and sandbox directories..."
+
+current_dir = `pwd`
+current_dir.strip!
+
+if ARGV.length >= 3
+  test_result_dir = ARGV[2]
+else
+  test_result_dir = "#{current_dir}/test-result"
+end
+puts "Test result directory: #{test_result_dir}"
+system("rm -Rf #{test_result_dir}")
+execute("mkdir #{test_result_dir}", "Cannot make directory #{test_result_dir}.")
+
+if ARGV.length >= 4
+  sandbox_dir = ARGV[3]
+else
+  sandbox_dir = "#{current_dir}/sandbox"
+end
+puts "Sandbox directory: #{sandbox_dir}"
+system("rm -Rf #{sandbox_dir}")
+execute("mkdir #{sandbox_dir}", "Cannot make directory #{sandbox_dir}")
+
+# Compile
+puts
+puts "Compiling..."
+execute("cp #{source_file} #{sandbox_dir}", "Cannot copy the source file to #{sandbox_dir}")
+begin 
+  Dir.chdir sandbox_dir
+rescue
+  puts "ERROR: Cannot change directory to #{sandbox_dir}."
+  exit(127)
+end
+execute("#{problem_home}/script/compile #{language} #{source_file}", "Compilation error!")
+compile_message = `cat compiler_message`
+compile_message.strip!
+execute("mv compiler_message #{test_result_dir}", "Cannot move the compiler message to #{test_result_dir}.")
+if compile_message != ""
+  puts "Cannot compile the source code. See message in #{test_result_dir}/compile_message"
+  exit(127)
+else
+  execute("mv a.out #{test_result_dir}", "Cannot move the compiled program to #{test_result_dir}")
+  system("rm -Rf #{sandbox_dir}/*")
+end
+
+require "#{problem_home}/script/test_dsl.rb"
+load "#{problem_home}/test_cases/all_tests.cfg"
+problem = Problem.get_instance
+
+if problem.well_formed? == false
+  puts "The problem specification is not well formed."
+  exit(127)
+end
+
+# Doing the testing.
+(1..(problem.num_tests)).each do |test_num|
+  puts
+  execute("cp #{test_result_dir}/a.out #{sandbox_dir}", "Cannot copy the compiled program into #{sandbox_dir}")
+  execute("#{problem_home}/script/run #{language} #{test_num}", "Error occured during execution of the run script")
+  execute("mkdir #{test_result_dir}/#{test_num}", "Cannot create directory #{test_result_dir}/#{test_num}")
+  execute("mv #{sandbox_dir}/result #{test_result_dir}/#{test_num}", "Cannot copy the result file into #{test_result_dir}/#{test_num}")
+  execute("mv #{sandbox_dir}/comment #{test_result_dir}/#{test_num}", "Cannot copy the comment file into #{test_result_dir}/#{test_num}")
+  execute("rm -Rf #{sandbox_dir}/*", "Cannot clear #{sandbox_dir}")
+end
+
+# Grade
+puts
+puts "Grading..."
+begin
+  Dir.chdir test_result_dir
+rescue
+  puts "ERROR: Cannot change directory to #{test_result_dir}."
+  exit(127)
+end
+execute("#{problem_home}/script/grade", "An error occured during grading!")
+
+puts
+puts "All done!"