diff --git a/pkgs/markdown/AUTHORS b/pkgs/markdown/AUTHORS
index 302a1de..213eca2 100644
--- a/pkgs/markdown/AUTHORS
+++ b/pkgs/markdown/AUTHORS
@@ -7,3 +7,4 @@
 
 David Peek <ninjascript@gmail.com>
 Daniel Schubert <daniel.schubert+github.com@gmail.com>
+Jirka Daněk <dnk@mail.muni.cz>
diff --git a/pkgs/markdown/pubspec.yaml b/pkgs/markdown/pubspec.yaml
index a659ba8..7740d41 100644
--- a/pkgs/markdown/pubspec.yaml
+++ b/pkgs/markdown/pubspec.yaml
@@ -6,6 +6,8 @@
 environment:
   sdk: '>=1.12.0 <2.0.0'
 dev_dependencies:
+  args: '^0.13.3+1'
   collection: ^1.2.0
   path: '^1.3.1'
   test: '^0.12.4+1'
+  yaml: '^2.1.8'
diff --git a/pkgs/markdown/tools/dartdoc-compare.dart b/pkgs/markdown/tools/dartdoc-compare.dart
new file mode 100644
index 0000000..05317b1
--- /dev/null
+++ b/pkgs/markdown/tools/dartdoc-compare.dart
@@ -0,0 +1,123 @@
+import 'dart:convert' show JSON;
+import 'dart:io' show Directory, File, Process;
+
+import 'package:args/args.dart' show ArgParser;
+import 'package:path/path.dart' show absolute;
+import 'package:yaml/yaml.dart' show loadYaml;
+
+int main(List<String> arguments) {
+  const dartdoc_dir = 'dartdoc-dir';
+  const markdown_before = 'before';
+  const markdown_after = 'after';
+  const sdk = 'sdk';
+  const help = 'help';
+  final parser = new ArgParser()
+    ..addSeparator("Usage: dartdoc-compare.dart [OPTIONS] <dart-package>")
+    ..addOption(dartdoc_dir, help: "Directory of the dartdoc package")
+    ..addOption(markdown_before, help: "Markdown package 'before' ref")
+    ..addOption(markdown_after,
+        defaultsTo: "HEAD", help: "Markdown package 'after' ref")
+    ..addFlag(sdk,
+        defaultsTo: false, negatable: false, help: "Is the package the SDK?")
+    ..addFlag(help, abbr: "h", hide: true);
+  var options = parser.parse(arguments);
+  if (options[help]) {
+    print(parser.usage);
+    return 0;
+  }
+  if (options[dartdoc_dir] == null || options[markdown_before] == null) {
+    print(
+        "Invalid arguments: Options --$dartdoc_dir and --$markdown_before must be specified");
+    print(parser.usage);
+    return 1;
+  }
+  var comparer = new DartdocCompare()
+    ..dartdoc_dir = options[dartdoc_dir]
+    ..markdown_before = options[markdown_before]
+    ..markdown_after = options[markdown_after]
+    ..dartdoc_bin = absolute(options[dartdoc_dir], "bin/dartdoc.dart")
+    ..dartdoc_pubspec_path = absolute(options[dartdoc_dir], "pubspec.yaml")
+    ..sdk = options[sdk];
+
+  var package = options.rest.first;
+  var success = comparer.compare(package);
+  return success ? 0 : 1;
+}
+
+class DartdocCompare {
+  String dartdoc_dir;
+  String markdown_before;
+  String markdown_after;
+  String dartdoc_bin;
+  String dartdoc_pubspec_path;
+  bool sdk;
+
+  bool compare(package) {
+    // Generate docs with Markdown "A".
+    var out_before = run_dartdoc(markdown_before, package);
+
+    // Generate docs with Markdown "B".
+    var out_after = run_dartdoc(markdown_after, package);
+
+    // Compare outputs
+    var diff = "diff -r -B ${out_before} ${out_after}";
+    var result = Process.runSync("${diff}", [], runInShell: true);
+    var nlines = "\n".allMatches(result.stdout).length;
+    print("Diff lines: ${ nlines }");
+    print(diff);
+    return result == 0;
+  }
+
+  run_dartdoc(markdown_ref, package) {
+    print("==========================================================");
+    print("Running dartdoc for ${markdown_ref}...");
+    print("==========================================================");
+    update_dartdoc_pubspec(markdown_ref);
+    return doInPath(package, () {
+      system('pub', ['get']);
+      var out = Directory.systemTemp
+          .createTempSync("dartdoc-compare-${markdown_ref}__");
+      var sdk_options = sdk ? "--sdk-docs --dart-sdk=$package" : "";
+      var cmd = "dart";
+      var args = ["${dartdoc_bin}", "--output=${out.path} ${sdk_options}"];
+      print("Command: $cmd ${args.join(" ")}");
+      system(cmd, args);
+      print("");
+
+      return out.path;
+    });
+  }
+
+  update_dartdoc_pubspec(markdown_ref) {
+      var dartdoc_pubspec =
+          loadYaml(new File(dartdoc_pubspec_path).readAsStringSync());
+      // make modifiable copy
+      dartdoc_pubspec = JSON.decode(JSON.encode(dartdoc_pubspec));
+
+      dartdoc_pubspec['dependencies']['markdown'] = {
+        'git': {
+          'url': 'git://github.com/dart-lang/markdown.git',
+          'ref': markdown_ref
+        }
+      };
+
+      new File(dartdoc_pubspec_path)
+          .writeAsStringSync(JSON.encode(dartdoc_pubspec));
+      return system('pub', ['get']);
+  }
+
+  static system(cmd, args) {
+    var result = Process.runSync(cmd, args);
+    print(result.stdout);
+    print(result.stderr);
+    return result.exitCode;
+  }
+
+  static doInPath(String path, Function f) {
+    var former = Directory.current.path;
+    Directory.current = path;
+    var result = f();
+    Directory.current = former;
+    return result;
+  }
+}