diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 00000000..8febba96
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1 @@
+*No changes yet!*
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 00000000..5c60afea
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,26 @@
+Copyright 2014, the Dart project authors. All rights reserved.
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+    * Neither the name of Google Inc. nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/README.md b/README.md
new file mode 100644
index 00000000..48637f21
--- /dev/null
+++ b/README.md
@@ -0,0 +1,72 @@
+The dart_style package defines an automatic, opinionated formatter for Dart
+code. It replaces the whitespace in your program with what it deems to be the
+best formatting for it. Resulting code should following the [Dart style guide][]
+but, moreso, should look nice to most human readers, most of the time.
+
+It handles indentation, inline whitespace and (by far the most difficult),
+intelligent line wrapping. It has no problems with nested collections, function
+expressions, long argument lists, or otherwise tricky code.
+
+## Running it
+
+The package exposes a simple command-line wrapper around the core formatting
+library. The easiest way to invoke it is to [globally activate][] the package
+and let pub put its executable on your path:
+
+    $ pub global activate dart_style
+    $ dartfmt ...
+
+If you don't want `dartfmt` on your path, you can run it explicitly:
+
+    $ pub global activate dart_style --no-executables
+    $ pub global run dart_style:format ...
+
+The formatter takes a list of paths, which can point to directories or files.
+If the path is a directory, it processes every `.dart` file in that directory
+or any of its subdirectories.
+
+By default, it formats each file and just prints the resulting code to stdout.
+If you pass `-w`, it will instead overwrite your existing files with the
+formatted results.
+
+You may pass an `--line-length` option to control the width of the page that it
+wraps lines to fit within, but you're strongly encouraged to keep the default
+line length of 80 columns.
+
+## Using it programmatically
+
+The package also exposes a single dart_style library containing a programmatic
+API for formatting code. Simple usage looks like this:
+
+    import 'package:dart_style/dart_style.dart';
+
+    main() {
+      var formatter = new DartFormatter();
+
+      try {
+        formatter.format("""
+        library an_entire_compilation_unit;
+
+        class SomeClass {}
+        """);
+
+        formatter.formatStatement("aSingle(statement);");
+      } on FormatterException catch (ex) {
+        print(ex);
+      }
+    }
+
+[dart style guide]: https://www.dartlang.org/articles/style-guide/
+[globally activate]: https://www.dartlang.org/tools/pub/cmd/pub-global.html
+
+## Stability
+
+You can rely on the formatter to not break your code or change its semantics.
+If it does do so, this is a critical bug and we'll fix it quickly.
+
+The heuristics the formatter uses to determine the "best" way to split a line
+are still being developed and may change over time. The ones today cover most
+common uses, but there's room for more refinement. We don't promise that code
+produced by the formatter today will be identical to the same code run through
+a later version of the formatter. We do hope that you'll like the output of the
+later version more.
\ No newline at end of file
diff --git a/bin/fmt.dart b/bin/fmt.dart
deleted file mode 100644
index bf21ac0c..00000000
--- a/bin/fmt.dart
+++ /dev/null
@@ -1,84 +0,0 @@
-import 'dart:io';
-
-import 'package:path/path.dart' as p;
-
-import 'package:dart_style/dart_style.dart';
-
-main(List<String> args) {
-  if (args.length == 1) {
-    if (new Directory(args[0]).existsSync()) {
-      reformatDirectory(args[0]);
-    } else if (new File(args[0]).existsSync()) {
-      reformatFile(args[0]);
-    } else {
-      // TODO(rnystrom): Report error.
-    }
-
-    return;
-  }
-
-  // This code is just for testing right now.
-
-  /*
-1234567890123456789012345678901234567890
-            */
-  formatStmt("sendPort.send({'type': 'error', 'error': 'oops'});");
-}
-
-void formatStmt(String source, [int pageWidth = 40]) {
-  var result = new DartFormatter(pageWidth: pageWidth).formatStatement(source);
-
-  drawRuler("before", pageWidth);
-  print(source);
-  drawRuler("after", pageWidth);
-  print(result);
-}
-
-void formatUnit(String source, [int pageWidth = 40]) {
-  var result = new DartFormatter(pageWidth: pageWidth).format(source);
-
-  drawRuler("before", pageWidth);
-  print(source);
-  drawRuler("after", pageWidth);
-  print(result);
-}
-
-void drawRuler(String label, int width) {
-  var padding = " " * (width - label.length - 1);
-  print("$label:$padding|");
-}
-
-/// Runs the formatter on every .dart file in [path] (and its subdirectories),
-/// and replaces them with their formatted output.
-void reformatDirectory(String path) {
-  for (var entry in new Directory(path).listSync(recursive: true)) {
-    if (!entry.path.endsWith(".dart")) continue;
-
-    var relative = p.relative(entry.path, from: path);
-    print(relative);
-
-    var formatter = new DartFormatter();
-    try {
-      var file = entry as File;
-      var source = file.readAsStringSync();
-      var formatted = formatter.format(source);
-      file.writeAsStringSync(formatted);
-      print("$relative: done");
-    } on FormatterException catch(err) {
-      print("$relative: failed with\n$err");
-    }
-  }
-}
-
-void reformatFile(String path) {
-  var formatter = new DartFormatter();
-  try {
-    var file = new File(path);
-    var source = file.readAsStringSync();
-    var formatted = formatter.format(source);
-    file.writeAsStringSync(formatted);
-    print("$path: done");
-  } on FormatterException catch(err) {
-    print("$path: failed with\n$err");
-  }
-}
diff --git a/bin/format.dart b/bin/format.dart
new file mode 100644
index 00000000..5dc4a4b1
--- /dev/null
+++ b/bin/format.dart
@@ -0,0 +1,108 @@
+import 'dart:io';
+
+import 'package:args/args.dart';
+import 'package:path/path.dart' as p;
+
+import 'package:dart_style/dart_style.dart';
+
+bool overwrite = false;
+int lineLength = 80;
+
+void main(List<String> args) {
+  var parser = new ArgParser();
+  parser.addFlag("help", abbr: "h", negatable: false,
+      help: "Shows usage information.");
+  parser.addOption("line-length", abbr: "l",
+      help: "Wrap lines longer than this.",
+      defaultsTo: "80");
+  parser.addFlag("overwrite", abbr: "w", negatable: false,
+      help: "Overwrite input files with formatted output.\n"
+            "If unset, prints results to standard output.");
+
+  var options = parser.parse(args);
+
+  if (options["help"]) {
+    printUsage(parser);
+    return;
+  }
+
+  overwrite = options["overwrite"];
+
+  try {
+    lineLength = int.parse(options["line-length"]);
+  } on FormatException catch (_) {
+    printUsage(parser, '--line-length must be an integer, was '
+                       '"${options['line-length']}".');
+    exitCode = 64;
+    return;
+  }
+
+  if (options.rest.isEmpty) {
+    printUsage(parser,
+        "Please provide at least one directory or file to format.");
+    exitCode = 64;
+    return;
+  }
+
+  for (var path in options.rest) {
+    var directory = new Directory(path);
+    if (directory.existsSync()) {
+      processDirectory(directory);
+      continue;
+    }
+
+    var file = new File(path);
+    if (file.existsSync()) {
+      processFile(file);
+    } else {
+      stderr.writeln('No file or directory found at "$path".');
+    }
+  }
+}
+
+void printUsage(ArgParser parser, [String error]) {
+  var output = stdout;
+
+  var message = "Reformats whitespace in Dart source files.";
+  if (error != null) {
+    message = error;
+    output = stdout;
+  }
+
+  output.write("""$message
+
+Usage: dartfmt [-l <line length>] <files or directories...>
+
+${parser.usage}
+""");
+}
+
+/// Runs the formatter on every .dart file in [path] (and its subdirectories),
+/// and replaces them with their formatted output.
+void processDirectory(Directory directory) {
+  print("Formatting directory ${directory.path}:");
+  for (var entry in directory.listSync(recursive: true)) {
+    if (!entry.path.endsWith(".dart")) continue;
+
+    var relative = p.relative(entry.path, from: directory.path);
+    processFile(entry, relative);
+  }
+}
+
+/// Runs the formatter on [file].
+void processFile(File file, [String label]) {
+  if (label == null) label = file.path;
+
+  var formatter = new DartFormatter(pageWidth: lineLength);
+  try {
+    var output = formatter.format(file.readAsStringSync());
+    if (overwrite) {
+      file.writeAsStringSync(output);
+      print("Formatted $label");
+    } else {
+      print(output);
+    }
+  } on FormatterException catch (err) {
+    stderr.writeln("Failed $label:\n$err");
+  }
+}
diff --git a/example/format.dart b/example/format.dart
new file mode 100644
index 00000000..9dca9f65
--- /dev/null
+++ b/example/format.dart
@@ -0,0 +1,29 @@
+import 'package:dart_style/dart_style.dart';
+
+void main(List<String> args) {
+  formatStmt("sendPort.send({'type': 'error', 'error': 'oops'});");
+  formatUnit("class Foo{}");
+}
+
+void formatStmt(String source, [int pageWidth = 40]) {
+  var result = new DartFormatter(pageWidth: pageWidth).formatStatement(source);
+
+  drawRuler("before", pageWidth);
+  print(source);
+  drawRuler("after", pageWidth);
+  print(result);
+}
+
+void formatUnit(String source, [int pageWidth = 40]) {
+  var result = new DartFormatter(pageWidth: pageWidth).format(source);
+
+  drawRuler("before", pageWidth);
+  print(source);
+  drawRuler("after", pageWidth);
+  print(result);
+}
+
+void drawRuler(String label, int width) {
+  var padding = " " * (width - label.length - 1);
+  print("$label:$padding|");
+}
\ No newline at end of file
diff --git a/lib/dart_style.dart b/lib/dart_style.dart
index fd90b671..494ab7e3 100644
--- a/lib/dart_style.dart
+++ b/lib/dart_style.dart
@@ -5,3 +5,4 @@
 library dart_style;
 
 export 'src/dart_formatter.dart';
+export 'src/formatter_exception.dart';
diff --git a/lib/src/dart_formatter.dart b/lib/src/dart_formatter.dart
index c9ca31f9..b77e110f 100644
--- a/lib/src/dart_formatter.dart
+++ b/lib/src/dart_formatter.dart
@@ -9,48 +9,11 @@ import 'package:analyzer/src/generated/parser.dart';
 import 'package:analyzer/src/generated/scanner.dart';
 import 'package:analyzer/src/generated/source.dart';
 
+import 'error_listener.dart';
 import 'source_visitor.dart';
 
-/// Thrown when an error occurs in formatting.
-class FormatterException implements Exception {
-  /// A message describing the error.
-  final String message;
-
-  /// Creates a new FormatterException with an optional error [message].
-  const FormatterException(this.message);
-
-  factory FormatterException.forErrors(List<AnalysisError> errors,
-      [LineInfo lines]) {
-    var buffer = new StringBuffer();
-
-    for (var error in errors) {
-      // Show position information if we have it.
-      var pos;
-      if (lines != null) {
-        var start = lines.getLocation(error.offset);
-        var end = lines.getLocation(error.offset + error.length);
-        pos = "${start.lineNumber}:${start.columnNumber}-";
-        if (start.lineNumber == end.lineNumber) {
-          pos += "${end.columnNumber}";
-        } else {
-          pos += "${end.lineNumber}:${end.columnNumber}";
-        }
-      } else {
-        pos = "${error.offset}...${error.offset + error.length}";
-      }
-      buffer.writeln("$pos: ${error.message}");
-    }
-
-    return new FormatterException(buffer.toString());
-  }
-
-  String toString() => message;
-}
-
-// TODO(rnystrom): We may not want to export this class publicly. At the very
-// least, making things like lineInfo public are weird.
 /// Dart source code formatter.
-class DartFormatter implements AnalysisErrorListener {
+class DartFormatter {
   /// The string that newlines should use.
   ///
   /// If not explicitly provided, this is inferred from the source text. If the
@@ -64,10 +27,6 @@ class DartFormatter implements AnalysisErrorListener {
   /// The number of levels of indentation to prefix the output lines with.
   final int indent;
 
-  final errors = <AnalysisError>[];
-
-  LineInfo lineInfo;
-
   /// Creates a new formatter for Dart code.
   ///
   /// If [lineEnding] is given, that will be used for any newlines in the
@@ -94,39 +53,30 @@ class DartFormatter implements AnalysisErrorListener {
   }
 
   String _format(String source, parseFn(Parser parser, Token start)) {
-    var startToken = _tokenize(source);
-    _checkForErrors();
+    var errorListener = new ErrorListener();
+    var startToken = _tokenize(source, errorListener);
+    errorListener.throwIfErrors();
 
-    var parser = new Parser(null, this);
+    var parser = new Parser(null, errorListener);
     parser.parseAsync = true;
 
     var node = parseFn(parser, startToken);
-    _checkForErrors();
+    errorListener.throwIfErrors();
 
     var buffer = new StringBuffer();
-    var visitor = new SourceVisitor(this, lineInfo, source, buffer);
+    var visitor = new SourceVisitor(this, errorListener.lineInfo, source,
+        buffer);
 
     visitor.run(node);
 
     return buffer.toString();
   }
 
-  void onError(AnalysisError error) {
-    errors.add(error);
-  }
-
-  /// Throws a [FormatterException] if any errors have been reported.
-  void _checkForErrors() {
-    if (errors.length > 0) {
-      throw new FormatterException.forErrors(errors, lineInfo);
-    }
-  }
-
-  Token _tokenize(String source) {
+  Token _tokenize(String source, ErrorListener errorListener) {
     var reader = new CharSequenceReader(source);
-    var scanner = new Scanner(null, reader, this);
+    var scanner = new Scanner(null, reader, errorListener);
     var token = scanner.tokenize();
-    lineInfo = new LineInfo(scanner.lineStarts);
+    errorListener.lineInfo = new LineInfo(scanner.lineStarts);
 
     // Infer the line ending if not given one. Do it here since now we know
     // where the lines start.
diff --git a/lib/src/error_listener.dart b/lib/src/error_listener.dart
new file mode 100644
index 00000000..9c5c0025
--- /dev/null
+++ b/lib/src/error_listener.dart
@@ -0,0 +1,28 @@
+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library dart_style.src.error_listener;
+
+import 'package:analyzer/analyzer.dart';
+import 'package:analyzer/src/generated/source.dart';
+
+import 'formatter_exception.dart';
+
+/// A simple [AnalysisErrorListener] that just collects the reported errors.
+class ErrorListener implements AnalysisErrorListener {
+  LineInfo lineInfo;
+
+  final _errors = <AnalysisError>[];
+
+  void onError(AnalysisError error) {
+    _errors.add(error);
+  }
+
+  /// Throws a [FormatterException] if any errors have been reported.
+  void throwIfErrors() {
+    if (_errors.isEmpty) return;
+
+    throw new FormatterException.forErrors(_errors, lineInfo);
+  }
+}
\ No newline at end of file
diff --git a/lib/src/formatter_exception.dart b/lib/src/formatter_exception.dart
new file mode 100644
index 00000000..bb4e1995
--- /dev/null
+++ b/lib/src/formatter_exception.dart
@@ -0,0 +1,44 @@
+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library dart_style.src.formatter_exception;
+
+import 'package:analyzer/analyzer.dart';
+import 'package:analyzer/src/generated/source.dart';
+
+/// Thrown when an error occurs in formatting.
+class FormatterException implements Exception {
+  /// A message describing the error.
+  final String message;
+
+  /// Creates a new FormatterException with an optional error [message].
+  const FormatterException(this.message);
+
+  factory FormatterException.forErrors(List<AnalysisError> errors,
+      [LineInfo lines]) {
+    var buffer = new StringBuffer();
+
+    for (var error in errors) {
+      // Show position information if we have it.
+      var pos;
+      if (lines != null) {
+        var start = lines.getLocation(error.offset);
+        var end = lines.getLocation(error.offset + error.length);
+        pos = "${start.lineNumber}:${start.columnNumber}-";
+        if (start.lineNumber == end.lineNumber) {
+          pos += "${end.columnNumber}";
+        } else {
+          pos += "${end.lineNumber}:${end.columnNumber}";
+        }
+      } else {
+        pos = "${error.offset}...${error.offset + error.length}";
+      }
+      buffer.writeln("$pos: ${error.message}");
+    }
+
+    return new FormatterException(buffer.toString());
+  }
+
+  String toString() => message;
+}
diff --git a/pubspec.lock b/pubspec.lock
index 11ff513b..4cd017b5 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -16,7 +16,7 @@ packages:
   collection:
     description: collection
     source: hosted
-    version: "1.0.0"
+    version: "1.1.0"
   logging:
     description: logging
     source: hosted
diff --git a/pubspec.yaml b/pubspec.yaml
index ffa6748e..840d13b8 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,7 +1,15 @@
 name: dart_style
+version: 0.1.0-dev
+description: Opinionated, automatic Dart source code formatter.
+author: "Dart Team <misc@dartlang.org>"
+homepage: https://github.com/dart-lang/dart_style
 dependencies:
   analyzer: ">=0.22.0 <0.23.0"
+  args: ">=0.12.1 <0.13.0"
+  path: ">=1.0.0 <2.0.0"
 dev_dependencies:
-  unittest: ">=0.11.0 <0.12.0"
   browser: ">=0.10.0 <0.11.0"
-  path: ">=1.0.0 <2.0.0"
\ No newline at end of file
+  unittest: ">=0.11.0 <0.12.0"
+executables:
+  dartfmt: format
+  
\ No newline at end of file