diff --git a/Jakefile.coffee b/Jakefile.coffee
index 8759bac..78e0cf2 100644
--- a/Jakefile.coffee
+++ b/Jakefile.coffee
@@ -20,7 +20,7 @@ task 'default', -> jake.exec ['jake -T'], EXEC_PRINT_OPTS
 
 # Used internally to compile JavaScript executable.
 # Invoked with compile command string.
-task 'build', async: true, ['validate'], (compile_cmd)->
+task '_build', async: true, ['validate'], (compile_cmd)->
   jake.exec [compile_cmd], ->
         addShebang JS_EXE
         complete()
@@ -28,11 +28,11 @@ task 'build', async: true, ['validate'], (compile_cmd)->
 
 desc 'Build JavaScript executable from CoffeeScript source.'
 task 'build.coffee', ->
-  jake.Task['build'].invoke "coffee -c '#{CS_SRC}'"
+  jake.Task['_build'].invoke "coffee -c '#{CS_SRC}'"
 
 desc 'Build JavaScript executable from TypeScript source.'
 task 'build.ts', ->
-  jake.Task['build'].invoke "tsc '#{TS_SRC}'"  
+  jake.Task['_build'].invoke "tsc '#{TS_SRC}'"  
 
 desc 'Validate package.json.'
 task 'validate', ->
@@ -52,7 +52,7 @@ task 'publish', async: true, [PUBLISHED_BUILD], ->
         complete()
       , breakOnError: false, printStdout: true, printStderr: true
       
-desc 'Commit with message in file COMMIT.'
+desc 'Commit to git with message in file COMMIT'
 task 'commit', [PUBLISHED_BUILD], ->
   jake.exec ['git commit -a -F COMMIT'], EXEC_PRINT_OPTS
 
diff --git a/README.asciidoc b/README.asciidoc
index bd3e341..ee1f7f7 100644
--- a/README.asciidoc
+++ b/README.asciidoc
@@ -61,8 +61,12 @@ home directory. For example:
 === Implementation
 The original version this program was
 https://srackham.wordpress.com/2010/03/23/command-line-sms-script/[written
-in Python] but this version is written in both CoffeeScript
-(`clisms.coffee`) and TypeScript (`clisms.ts`) as a learning exercise.
+in Python] but this version is written in CoffeeScript
+(`clisms.coffee`), TypeScript (`clisms.ts`) and Dart (`clisms.dart`) as a learning exercise.
+
 The compiled node executable `clisms.js` file can be generated from
 either version (use the `jake build-coffee` command to compile
 `clisms.coffee`, `jake build-ts` command to compile `clisms.ts`.
+
+The Dart version should be run using the command-line Dart VM (`dart
+clisms.dart`), I got errors compiling it with `dart2js`.
diff --git a/clisms.dart b/clisms.dart
new file mode 100644
index 0000000..2353e18
--- /dev/null
+++ b/clisms.dart
@@ -0,0 +1,231 @@
+import 'dart:io';
+import 'dart:json';
+import 'dart:uri';
+
+MAN_PAGE() => '''
+
+NAME
+  ${PROG} - Send SMS message
+
+SYNOPSIS
+  ${PROG} PHONE MESSAGE
+  ${PROG} -s MSGID
+  ${PROG} -b | -l | -p
+
+DESCRIPTION
+  A simple command-line script to send SMS messages using
+  Clickatell's HTTP API (see http://clickatell.com).
+  Records messages log in ${LOG_FILE}.
+  Reads configuration parameters from ${CONF_FILE}
+  Version ${VERSION} executed from Dart source.
+
+OPTIONS
+  -s MSGID
+    Query message delivery status.
+
+  -b
+    Query account balance.
+
+  -l
+    List message log file using ${PAGER}.
+
+  -p
+    List phone book.
+
+AUTHOR
+  Written by Stuart Rackham, <srackham@gmail.com>
+
+COPYING
+  Copyright (C) 2012 Stuart Rackham. Free use of this software is
+  granted under the terms of the MIT License.
+''';
+
+const VERSION = '0.4.1';
+
+// Clickatell account configuration parameters.
+// The configuration file is single JSON formatted object with the
+// same attributes and attribute types as the default CONF variable below.
+// Alternatively you could dispense with the configuration file and edit the
+// values in the CONF variable below.
+final CONF = {
+  'USERNAME': '',
+  'PASSWORD': '',
+  'API_ID': '',
+  'SENDER_ID': '',  // Your registered mobile phone number.
+  'PHONE_BOOK': {}
+};
+
+
+int ARGC;
+List<String> ARGV;
+String PROG;
+String HOME;
+String PAGER;
+Path LOG_FILE;
+Path CONF_FILE;
+
+void main() {
+  Options OPTS = new Options();
+  ARGV = OPTS.arguments;
+  ARGC = ARGV.length;
+  PROG = new Path(OPTS.script).filename;
+  HOME = Platform.environment['HOME'];
+  HOME = HOME == null ? Platform.environment['HOMEPATH'] : HOME;
+  PAGER = Platform.environment['PAGER'];
+  if (PAGER == null) PAGER = 'less';
+  LOG_FILE = new Path(HOME).join(new Path('clisms.log'));
+  CONF_FILE = new Path(HOME).join(new Path('.clisms.json'));
+  var f = new File.fromPath(CONF_FILE);
+  if (f.existsSync()) {
+    CONF = JSON.parse(f.readAsTextSync());
+  }
+
+  if (ARGC == 2) {
+    if (ARGV[0] == '-s')
+      printMessageStatus(ARGV[1]);
+    else
+      sendMessage(ARGV[0], ARGV[1]);
+  }
+  else if (ARGC == 1) {
+    switch (ARGV[0]) {
+      case '-b':
+        printAccountBalance();
+        break;
+      case '-l':  // View log file in pager.
+        shell(PAGER, [LOG_FILE.toString()], (exitCode) => exit(exitCode));
+        break;
+      case '-p':
+        CONF['PHONE_BOOK'].forEach(
+            (name, number) => print('${name}: ${number}')
+        );
+        break;
+      default:
+        die('Illegal option: ${ARGV[0]}');
+    }
+  }
+  else
+    print(MAN_PAGE());
+}
+
+// URL query string parameters.
+final QUERY = {
+  'user':   CONF['USERNAME'],
+  'password': CONF['PASSWORD'],
+  'api_id':   CONF['API_ID'],
+  'concat':   3,
+  'req_feat': 32  // Gateway must support numeric sender ID.
+};
+
+// Clickatell status messages.
+final MSG_STATUS = {
+  '001': 'message unknown',
+  '002': 'message queued',
+  '003': 'delivered to gateway',
+  '004': 'received by recipient',
+  '005': 'error with message',
+  '007': 'error delivering message',
+  '008': 'OK',
+  '009': 'routing error',
+  '012': 'out of credit'
+};
+
+// Execute shell command. 'cmd' is executable path; 'args' is arguments array;
+// 'onExit' is executed and passed the process exit code when the command
+// exits.
+void shell(String cmd, List<String> args, void onExit(int exitCode)) {
+  var p = Process.start(cmd, args);
+  p.stdout.pipe(stdout);
+  stdin.pipe(p.stdin);
+  p.onExit = (exitCode) {
+    p.close();
+    onExit(exitCode);
+  };
+}
+
+/**
+Execute Clickatell HTTP command.
+The `processResponse` function is called with the HTTP response data string.
+*/
+void httpCmd(String cmd, void processResponse(String data)) {
+  // Encode URI query parameters.
+  var params = [];
+  QUERY.forEach((k, v) {
+    params.add('${encodeUriComponent(k.toString())}='
+        '${encodeUriComponent(v.toString())}');
+    });
+  var query = Strings.join(params, '&');
+  var httpClient = new HttpClient();
+  HttpClientConnection conn = httpClient.get(
+      'api.clickatell.com', 80, '/http/${cmd}?${query}');
+  conn.onResponse = (HttpClientResponse response) {
+    StringInputStream stream = new StringInputStream(response.inputStream);
+    StringBuffer data = new StringBuffer();
+    stream.onData = () => data.add(stream.read());
+    stream.onClosed = () {
+      processResponse(data.toString());
+    };
+  };
+}
+
+/// Print the status of a previously sent message.
+void printMessageStatus(String messageId) {
+  QUERY['apimsgid'] = messageId;
+  httpCmd('getmsgcharge', (data) {
+    //TODO String.slice(startIndex, [endIndex])) method and Map.get(k, ifAbsent)
+    //     s = MSG_STATUS.get(data.slice(-3), '');
+    //     ifAbsent is var not function (belts and braces overkill).
+    var i = data.length - 3;
+    if (i < 0) i = 0;
+    var s = MSG_STATUS[data.substring(i)];
+    if (s == null) s = '';
+    print('$data  ($s)');
+  });
+}
+
+// Strip number punctuation and check the number is not obviously illegal.
+String sanitizePhoneNumber(String number) {
+  var result = number.replaceAll(new RegExp(r'[+ ()-]'), '');
+  if (! new RegExp(r'^\d+$').hasMatch(result)) {
+    die('illegal phone number: ${number}');
+  }
+  return result;
+}
+
+// Send text message. The recipient phone number can be a phone number
+// or the name of a phone book entry.
+void sendMessage(String to, String text) {
+  var name;
+  if (CONF['PHONE_BOOK'][to] != null) {
+    name = to;
+    to = CONF['PHONE_BOOK'][to];
+  }
+  to = sanitizePhoneNumber(to);
+  var sender_id = sanitizePhoneNumber(CONF['SENDER_ID']);
+  QUERY['from'] = sender_id;
+  QUERY['to'] = to;
+  QUERY['text'] = text;
+  httpCmd('sendmsg', (result) {
+    var now = new Date.now();
+    if (name != null) to = '$to: $name';
+    OutputStream out = new File.fromPath(LOG_FILE)
+        .openOutputStream(FileMode.APPEND);
+    out.writeString('''
+to:   ${to}
+from: ${sender_id}
+date: ${now.toString()}
+result: ${result}
+text: ${text}\n
+''');
+    out.close();
+    print(result);
+  });
+}
+
+void printAccountBalance() {
+  httpCmd('getbalance', (data) => print(data));
+}
+
+void die(String message, [int status=1]) {
+  stderr.writeString(message);
+  exit(status);
+}