diff --git a/create_sdk.gyp b/create_sdk.gyp
index 769f502e289..749cda561a3 100644
--- a/create_sdk.gyp
+++ b/create_sdk.gyp
@@ -20,14 +20,15 @@
         {
           'action_name': 'create_sdk_py',
           'inputs': [
-            # This is neccessary because we have all the pub test files inside
-            # the pub directory instead of in tests/pub. Xcode can only handle
-            # a certain amount of files in one list (also depending on the
-            # length of the path from where you run). This regexp excludes
-            # pub/test
+            # Xcode can only handle a certain amount of files in one list
+            # (also depending on the length of the path from where you run).
             '<!@(["python", "tools/list_files.py",'
-                '"^(?!.*pub/test).*dart$",'
+                '"dart$",'
                 '"sdk/lib"])',
+            'sdk/lib/dart2dart.platform',
+            'sdk/lib/dart_client.platform',
+            'sdk/lib/dart_server.platform',
+            'sdk/lib/dart_shared.platform',
             '<!@(["python", "tools/list_files.py", "", '
                 '"sdk/lib/_internal/js_runtime/lib/preambles"])',
             '<!@(["python", "tools/list_files.py", "", "sdk/bin"])',
diff --git a/pkg/compiler/lib/src/apiimpl.dart b/pkg/compiler/lib/src/apiimpl.dart
index 7620392ddc9..33f2e7f9dc0 100644
--- a/pkg/compiler/lib/src/apiimpl.dart
+++ b/pkg/compiler/lib/src/apiimpl.dart
@@ -14,7 +14,6 @@ import 'package:package_config/src/packages_impl.dart' show
     NonFilePackagesDirectoryPackages;
 import 'package:package_config/src/util.dart' show
     checkValidPackageUri;
-import 'package:sdk_library_metadata/libraries.dart' as library_info;
 
 import '../compiler_new.dart' as api;
 import 'commandline_options.dart';
@@ -28,17 +27,24 @@ import 'diagnostics/messages.dart' show
     Message;
 import 'elements/elements.dart' as elements;
 import 'io/source_file.dart';
+import 'platform_configuration.dart' as platform_configuration;
 import 'script.dart';
 
 const bool forceIncrementalSupport =
     const bool.fromEnvironment('DART2JS_EXPERIMENTAL_INCREMENTAL_SUPPORT');
 
+/// Locations of the platform descriptor files relative to the library root.
+const String _clientPlatform = "lib/dart_client.platform";
+const String _serverPlatform = "lib/dart_server.platform";
+const String _sharedPlatform = "lib/dart_shared.platform";
+const String _dart2dartPlatform = "lib/dart2dart.platform";
+
 /// Implements the [Compiler] using a [api.CompilerInput] for supplying the
 /// sources.
 class CompilerImpl extends Compiler {
   api.CompilerInput provider;
   api.CompilerDiagnostics handler;
-  final Uri libraryRoot;
+  final Uri platformConfigUri;
   final Uri packageConfig;
   final Uri packageRoot;
   final api.PackagesDiscoveryProvider packagesDiscoveryProvider;
@@ -46,23 +52,29 @@ class CompilerImpl extends Compiler {
   List<String> options;
   Map<String, dynamic> environment;
   bool mockableLibraryUsed = false;
-  final Set<library_info.Category> allowedLibraryCategories;
+
+  /// A mapping of the dart: library-names to their location.
+  ///
+  /// Initialized in [setupSdk].
+  Map<String, Uri> sdkLibraries;
 
   GenericTask userHandlerTask;
   GenericTask userProviderTask;
   GenericTask userPackagesDiscoveryTask;
 
+  Uri get libraryRoot => platformConfigUri.resolve(".");
+
   CompilerImpl(this.provider,
            api.CompilerOutput outputProvider,
            this.handler,
-           this.libraryRoot,
+           Uri libraryRoot,
            this.packageRoot,
            List<String> options,
            this.environment,
            [this.packageConfig,
             this.packagesDiscoveryProvider])
       : this.options = options,
-        this.allowedLibraryCategories = getAllowedLibraryCategories(options),
+        this.platformConfigUri = resolvePlatformConfig(libraryRoot, options),
         super(
             outputProvider: outputProvider,
             enableTypeAssertions: hasOption(options, Flags.enableCheckedMode),
@@ -175,31 +187,35 @@ class CompilerImpl extends Compiler {
     return const <String>[];
   }
 
-  static Set<library_info.Category> getAllowedLibraryCategories(
-      List<String> options) {
-    Iterable<library_info.Category> categories =
-      extractCsvOption(options, '--categories=')
-          .map(library_info.parseCategory)
-          .where((x) => x != null);
-    if (categories.isEmpty) {
-      return new Set.from([library_info.Category.client]);
+  static Uri resolvePlatformConfig(Uri libraryRoot,
+                                   List<String> options) {
+    String platformConfigPath =
+        extractStringOption(options, "--platform-config=", null);
+    if (platformConfigPath != null) {
+      return libraryRoot.resolve(platformConfigPath);
+    } else if (hasOption(options, '--output-type=dart')) {
+      return libraryRoot.resolve(_dart2dartPlatform);
+    } else {
+      Iterable<String> categories = extractCsvOption(options, '--categories=');
+      if (categories.length == 0) {
+        return libraryRoot.resolve(_clientPlatform);
+      }
+      assert(categories.length <= 2);
+      if (categories.contains("Client")) {
+        if (categories.contains("Server")) {
+          return libraryRoot.resolve(_sharedPlatform);
+        }
+        return libraryRoot.resolve(_clientPlatform);
+      }
+      assert(categories.contains("Server"));
+      return libraryRoot.resolve(_serverPlatform);
     }
-    return new Set.from(categories);
   }
 
   static bool hasOption(List<String> options, String option) {
     return options.indexOf(option) >= 0;
   }
 
-  String lookupPatchPath(String dartLibraryName) {
-    library_info.LibraryInfo info = lookupLibraryInfo(dartLibraryName);
-    if (info == null) return null;
-    if (!info.isDart2jsLibrary) return null;
-    String path = info.dart2jsPatchPath;
-    if (path == null) return null;
-    return "lib/$path";
-  }
-
   void log(message) {
     callUserHandler(
         null, null, null, null, message, api.Diagnostic.VERBOSE_INFO);
@@ -304,81 +320,58 @@ class CompilerImpl extends Compiler {
   }
 
   /// Translates "resolvedUri" with scheme "dart" to a [uri] resolved relative
-  /// to [libraryRoot] according to the information in [library_info.libraries].
+  /// to [platformConfigUri] according to the information in the file at
+  /// [platformConfigUri].
   ///
   /// Returns null and emits an error if the library could not be found or
   /// imported into [importingLibrary].
   ///
-  /// If [importingLibrary] is a platform or patch library all dart2js libraries
-  /// can be resolved. Otherwise only libraries with categories in
-  /// [allowedLibraryCategories] can be resolved.
+  /// Internal libraries (whose name starts with '_') can be only resolved if
+  /// [importingLibrary] is a platform or patch library.
   Uri translateDartUri(elements.LibraryElement importingLibrary,
                        Uri resolvedUri, Spannable spannable) {
 
-    library_info.LibraryInfo libraryInfo = lookupLibraryInfo(resolvedUri.path);
+    Uri location = lookupLibraryUri(resolvedUri.path);
 
-    bool allowInternalLibraryAccess = false;
-    if (importingLibrary != null) {
-      if (importingLibrary.isPlatformLibrary || importingLibrary.isPatch) {
-        allowInternalLibraryAccess = true;
-      } else if (importingLibrary.canonicalUri.path.contains(
-          'sdk/tests/compiler/dart2js_native')) {
-        allowInternalLibraryAccess = true;
-      }
+    if (location == null) {
+      reporter.reportErrorMessage(
+          spannable,
+          MessageKind.LIBRARY_NOT_FOUND,
+          {'resolvedUri': resolvedUri});
+      return null;
     }
 
-    String computePath() {
-      if (libraryInfo == null) {
-        return null;
-      } else if (!libraryInfo.isDart2jsLibrary) {
-        return null;
-      } else {
-        if (libraryInfo.isInternal &&
-            !allowInternalLibraryAccess) {
-          if (importingLibrary != null) {
-            reporter.reportErrorMessage(
-                spannable,
-                MessageKind.INTERNAL_LIBRARY_FROM,
-                {'resolvedUri': resolvedUri,
-                  'importingUri': importingLibrary.canonicalUri});
-          } else {
-            reporter.reportErrorMessage(
-                spannable,
-                MessageKind.INTERNAL_LIBRARY,
-                {'resolvedUri': resolvedUri});
-            registerDisallowedLibraryUse(resolvedUri);
-          }
-          return null;
-        } else if (!allowInternalLibraryAccess &&
-            !allowedLibraryCategories.any(libraryInfo.categories.contains)) {
-          registerDisallowedLibraryUse(resolvedUri);
-          // TODO(sigurdm): Currently we allow the sdk libraries to import
-          // libraries from any category. We might want to revisit this.
-          return null;
+    if (resolvedUri.path.startsWith('_')  ) {
+      bool allowInternalLibraryAccess = importingLibrary != null &&
+          (importingLibrary.isPlatformLibrary ||
+              importingLibrary.isPatch ||
+              importingLibrary.canonicalUri.path
+                  .contains('sdk/tests/compiler/dart2js_native'));
+
+      if (!allowInternalLibraryAccess) {
+        if (importingLibrary != null) {
+          reporter.reportErrorMessage(
+              spannable,
+              MessageKind.INTERNAL_LIBRARY_FROM,
+              {'resolvedUri': resolvedUri,
+                'importingUri': importingLibrary.canonicalUri});
         } else {
-          return (libraryInfo.dart2jsPath != null)
-              ? libraryInfo.dart2jsPath
-              : libraryInfo.path;
+          reporter.reportErrorMessage(
+              spannable,
+              MessageKind.INTERNAL_LIBRARY,
+              {'resolvedUri': resolvedUri});
+          registerDisallowedLibraryUse(resolvedUri);
         }
+        return null;
       }
     }
 
-    String path = computePath();
-
-    if (path == null) {
-      if (libraryInfo == null) {
-        reporter.reportErrorMessage(
-            spannable,
-            MessageKind.LIBRARY_NOT_FOUND,
-            {'resolvedUri': resolvedUri});
-      } else {
-        reporter.reportErrorMessage(
-            spannable,
-            MessageKind.LIBRARY_NOT_SUPPORTED,
-            {'resolvedUri': resolvedUri});
-      }
-      // TODO(johnniwinther): Support signaling the error through the returned
-      // value.
+    if (location.scheme == "unsupported") {
+      reporter.reportErrorMessage(
+          spannable,
+          MessageKind.LIBRARY_NOT_SUPPORTED,
+          {'resolvedUri': resolvedUri});
+      registerDisallowedLibraryUse(resolvedUri);
       return null;
     }
 
@@ -388,13 +381,7 @@ class CompilerImpl extends Compiler {
       // supports this use case better.
       mockableLibraryUsed = true;
     }
-    return libraryRoot.resolve("lib/$path");
-  }
-
-  Uri resolvePatchUri(String dartLibraryPath) {
-    String patchPath = lookupPatchPath(dartLibraryPath);
-    if (patchPath == null) return null;
-    return libraryRoot.resolve(patchPath);
+    return location;
   }
 
   Uri translatePackageUri(Spannable node, Uri uri) {
@@ -420,11 +407,14 @@ class CompilerImpl extends Compiler {
   Future<elements.LibraryElement> analyzeUri(
       Uri uri,
       {bool skipLibraryWithPartOfTag: true}) {
-    if (packages == null) {
-      return setupPackages(uri).then((_) => super.analyzeUri(uri));
+    List<Future> setupFutures = new List<Future>();
+    if (sdkLibraries == null) {
+      setupFutures.add(setupSdk());
     }
-    return super.analyzeUri(
-        uri, skipLibraryWithPartOfTag: skipLibraryWithPartOfTag);
+    if (packages == null) {
+      setupFutures.add(setupPackages(uri));
+    }
+    return Future.wait(setupFutures).then((_) => super.analyzeUri(uri));
   }
 
   Future setupPackages(Uri uri) {
@@ -465,10 +455,24 @@ class CompilerImpl extends Compiler {
     return new Future.value();
   }
 
-  Future<bool> run(Uri uri) {
-    log('Allowed library categories: $allowedLibraryCategories');
+  Future<Null> setupSdk() {
+    if (sdkLibraries == null) {
+      return platform_configuration.load(platformConfigUri, provider)
+          .then((Map<String, Uri> mapping) {
+        sdkLibraries = mapping;
+      });
+    } else {
+      // The incremental compiler sets up the sdk before run.
+      // Therefore this will be called a second time.
+      return new Future.value(null);
+    }
+  }
 
-    return setupPackages(uri).then((_) {
+  Future<bool> run(Uri uri) {
+    log('Using platform configuration at ${platformConfigUri}');
+
+    return Future.wait([setupSdk(), setupPackages(uri)]).then((_) {
+      assert(sdkLibraries != null);
       assert(packages != null);
 
       return super.run(uri).then((bool success) {
@@ -559,10 +563,15 @@ class CompilerImpl extends Compiler {
     }
   }
 
-
   fromEnvironment(String name) => environment[name];
 
-  library_info.LibraryInfo lookupLibraryInfo(String libraryName) {
-    return library_info.libraries[libraryName];
+  Uri lookupLibraryUri(String libraryName) {
+    assert(invariant(NO_LOCATION_SPANNABLE,
+        sdkLibraries != null, message: "setupSdk() has not been run"));
+    return sdkLibraries[libraryName];
+  }
+
+  Uri resolvePatchUri(String libraryName) {
+    return backend.resolvePatchUri(libraryName, platformConfigUri);
   }
 }
diff --git a/pkg/compiler/lib/src/common/backend_api.dart b/pkg/compiler/lib/src/common/backend_api.dart
index bdfcf79d0ed..04caaf8f47c 100644
--- a/pkg/compiler/lib/src/common/backend_api.dart
+++ b/pkg/compiler/lib/src/common/backend_api.dart
@@ -412,6 +412,12 @@ abstract class Backend {
                            Element element,
                            CallStructure callStructure,
                            ForeignResolver resolver) {}
+
+  /// Returns the location of the patch-file associated with [libraryName]
+  /// resolved from [plaformConfigUri].
+  ///
+  /// Returns null if there is none.
+  Uri resolvePatchUri(String libraryName, Uri plaformConfigUri);
 }
 
 /// Interface for resolving calls to foreign functions.
diff --git a/pkg/compiler/lib/src/compiler.dart b/pkg/compiler/lib/src/compiler.dart
index d07dbd2ac86..271136aa645 100644
--- a/pkg/compiler/lib/src/compiler.dart
+++ b/pkg/compiler/lib/src/compiler.dart
@@ -929,7 +929,7 @@ abstract class Compiler {
     }
   }
 
-  /// Analyze all member of the library in [libraryUri].
+  /// Analyze all members of the library in [libraryUri].
   ///
   /// If [skipLibraryWithPartOfTag] is `true`, member analysis is skipped if the
   /// library has a `part of` tag, assuming it is a part and not a library.
diff --git a/pkg/compiler/lib/src/dart_backend/backend.dart b/pkg/compiler/lib/src/dart_backend/backend.dart
index 5db667a7cec..de758c125cd 100644
--- a/pkg/compiler/lib/src/dart_backend/backend.dart
+++ b/pkg/compiler/lib/src/dart_backend/backend.dart
@@ -355,6 +355,12 @@ class DartBackend extends Backend {
         node, MessageKind.DEFERRED_LIBRARY_DART_2_DART);
     return false;
   }
+
+  @override
+  Uri resolvePatchUri(String libraryName, Uri) {
+    // Dart2dart does not use patches.
+    return null;
+  }
 }
 
 class DartImpactTransformer extends ImpactTransformer {
diff --git a/pkg/compiler/lib/src/js_backend/backend.dart b/pkg/compiler/lib/src/js_backend/backend.dart
index 6236ed0202a..62c863cd519 100644
--- a/pkg/compiler/lib/src/js_backend/backend.dart
+++ b/pkg/compiler/lib/src/js_backend/backend.dart
@@ -2577,6 +2577,28 @@ class JavaScriptBackend extends Backend {
     }
     return rewriter.rewrite(code);
   }
+
+  /// The locations of js patch-files relative to the sdk-descriptors.
+  static const _patchLocations = const <String, String>{
+    "async": "_internal/js_runtime/lib/async_patch.dart",
+    "collection":  "_internal/js_runtime/lib/collection_patch.dart",
+    "convert": "_internal/js_runtime/lib/convert_patch.dart",
+    "core": "_internal/js_runtime/lib/core_patch.dart",
+    "developer": "_internal/js_runtime/lib/developer_patch.dart",
+    "io": "_internal/js_runtime/lib/io_patch.dart",
+    "isolate": "_internal/js_runtime/lib/isolate_patch.dart",
+    "math": "_internal/js_runtime/lib/math_patch.dart",
+    "mirrors": "_internal/js_runtime/lib/mirrors_patch.dart",
+    "typed_data": "_internal/js_runtime/lib/typed_data_patch.dart",
+    "_internal": "_internal/js_runtime/lib/internal_patch.dart"
+  };
+
+  @override
+  Uri resolvePatchUri(String libraryName, Uri platformConfigUri) {
+    String patchLocation = _patchLocations[libraryName];
+    if (patchLocation == null) return null;
+    return platformConfigUri.resolve(patchLocation);
+  }
 }
 
 /// Handling of special annotations for tests.
diff --git a/pkg/compiler/lib/src/platform_configuration.dart b/pkg/compiler/lib/src/platform_configuration.dart
new file mode 100644
index 00000000000..41da852868b
--- /dev/null
+++ b/pkg/compiler/lib/src/platform_configuration.dart
@@ -0,0 +1,142 @@
+// Copyright (c) 2015, the Fletch 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.md file.
+
+/// Tools for loading and parsing platform-configuration files.
+library plaform_configuration;
+
+import "dart:async";
+import "package:charcode/ascii.dart";
+import "../compiler_new.dart" as api;
+
+/// Parses an Ini-like format.
+///
+/// Sections are initialized with a name enclosed in brackets.
+/// Each section contain zero or more properties of the form "name:value".
+/// Empty lines are ignored.
+/// Lines starting with # are ignored.
+/// Duplicate names are not allowed.
+/// All keys and values will be passed through [String.trim].
+///
+/// If an error is found, a [FormatException] is thrown, using [sourceUri] in
+/// the error message.
+///
+/// Example
+/// ```
+/// [a]
+/// b:c
+///
+/// [d]
+/// e:file:///tmp/bla
+/// ```
+/// Will parse to {"a": {"b":"c"}, "d": {"e": "file:///tmp/bla"}}.
+
+Map<String, Map<String, String>> parseIni(List<int> source,
+    {Set<String> allowedSections, Uri sourceUri}) {
+  int startOfLine = 0;
+  int currentLine = 0;
+
+  error(String message, int index) {
+    int column = index - startOfLine + 1;
+    throw new FormatException(
+        "$sourceUri:$currentLine:$column: $message", sourceUri, index);
+  }
+
+  Map<String, Map<String, String>> result =
+      new Map<String, Map<String, String>>();
+  Map<String, String> currentSection = null;
+
+  if (source.length == 0) return result;
+  bool endOfFile = false;
+
+  // Iterate once per $lf in file.
+  while (!endOfFile) {
+    currentLine += 1;
+    int endOfLine = source.indexOf($lf, startOfLine);
+    if (endOfLine == -1) {
+      // The dart2js provider adds a final 0 to the file.
+      endOfLine = source.last == 0 ? source.length - 1 : source.length;
+      endOfFile = true;
+    }
+    if (startOfLine != endOfLine) {
+      int firstChar = source[startOfLine];
+      if (firstChar == $hash) {
+        // Comment, do nothing.
+      } else if (firstChar == $open_bracket) {
+        // Section header
+        int endOfHeader = source.indexOf($close_bracket, startOfLine);
+        if (endOfHeader == -1) {
+          error("'[' must be matched by ']' on the same line.", startOfLine);
+        }
+        if (endOfHeader == startOfLine + 1) {
+          error("Empty header name", startOfLine + 1);
+        }
+        if (endOfHeader != endOfLine - 1) {
+          error("Section heading lines must end with ']'", endOfHeader + 1);
+        }
+        int startOfSectionName = startOfLine + 1;
+        String sectionName = new String.fromCharCodes(
+            source, startOfSectionName, endOfHeader).trim();
+        currentSection = new Map<String, String>();
+        if (result.containsKey(sectionName)) {
+          error("Duplicate section name '$sectionName'", startOfSectionName);
+        }
+        if (allowedSections != null && !allowedSections.contains(sectionName)) {
+          error("Unrecognized section name '$sectionName'", startOfSectionName);
+        }
+        result[sectionName] = currentSection;
+      } else {
+        // Property line
+        if (currentSection == null) {
+          error("Property outside section", startOfLine);
+        }
+        int separator = source.indexOf($colon, startOfLine);
+        if (separator == startOfLine) {
+          error("Empty property name", startOfLine);
+        }
+        if (separator == -1 || separator > endOfLine) {
+          error("Property line without ':'", startOfLine);
+        }
+        String propertyName =
+            new String.fromCharCodes(source, startOfLine, separator).trim();
+        if (currentSection.containsKey(propertyName)) {
+          error("Duplicate property name '$propertyName'", startOfLine);
+        }
+        String propertyValue =
+            new String.fromCharCodes(source, separator + 1, endOfLine).trim();
+        currentSection[propertyName] = propertyValue;
+      }
+    }
+    startOfLine = endOfLine + 1;
+  }
+  return result;
+}
+
+const String librariesSection = "libraries";
+const String dartSpecSection = "dart-spec";
+const String featuresSection = "features";
+
+Map<String, Uri> libraryMappings(
+    Map<String, Map<String, String>> sections, Uri baseLocation) {
+  assert(sections.containsKey(librariesSection));
+  Map<String, Uri> result = new Map<String, Uri>();
+  sections[librariesSection].forEach((String name, String value) {
+    result[name] = baseLocation.resolve(value);
+  });
+  return result;
+}
+
+final Set<String> allowedSections =
+    new Set.from([librariesSection, dartSpecSection, featuresSection]);
+
+Future<Map<String, Uri>> load(Uri location, api.CompilerInput provider) {
+  return provider.readFromUri(location).then((contents) {
+    if (contents is String) {
+      contents = contents.codeUnits;
+    }
+    return libraryMappings(
+        parseIni(contents,
+            allowedSections: allowedSections, sourceUri: location),
+        location);
+  });
+}
diff --git a/pkg/compiler/samples/darttags/darttags.dart b/pkg/compiler/samples/darttags/darttags.dart
index 2000b9be843..84b7562fc6c 100644
--- a/pkg/compiler/samples/darttags/darttags.dart
+++ b/pkg/compiler/samples/darttags/darttags.dart
@@ -87,10 +87,11 @@ main(List<String> arguments) {
   // Prepend "dart:" to the names.
   uris.addAll(names.map((String name) => Uri.parse('dart:$name')));
 
-  Uri libraryRoot = myLocation.resolve(SDK_ROOT);
+  Uri platformConfigUri = myLocation.resolve(SDK_ROOT)
+      .resolve("lib/dart2js_shared_sdk");
   Uri packageRoot = Uri.base.resolve(Platform.packageRoot);
 
-  analyze(uris, libraryRoot, packageRoot, handler.provider, handler)
+  analyze(uris, platformConfigUri, packageRoot, handler.provider, handler)
       .then(processMirrors);
 }
 
diff --git a/pkg/dart2js_incremental/lib/caching_compiler.dart b/pkg/dart2js_incremental/lib/caching_compiler.dart
index e2307dcdd4b..4185df1c46b 100644
--- a/pkg/dart2js_incremental/lib/caching_compiler.dart
+++ b/pkg/dart2js_incremental/lib/caching_compiler.dart
@@ -76,13 +76,16 @@ Future<CompilerImpl> reuseCompiler(
         ..needsStructuredMemberInfo = true;
 
     Uri core = Uri.parse("dart:core");
-    return compiler.libraryLoader.loadLibrary(core).then((_) {
-      // Likewise, always be prepared for runtimeType support.
-      // TODO(johnniwinther): Add global switch to force RTI.
-      compiler.enabledRuntimeType = true;
-      backend.registerRuntimeType(
-          compiler.enqueuer.resolution, compiler.globalDependencies);
-      return compiler;
+
+    return compiler.setupSdk().then((_) {
+      return compiler.libraryLoader.loadLibrary(core).then((_) {
+        // Likewise, always be prepared for runtimeType support.
+        // TODO(johnniwinther): Add global switch to force RTI.
+        compiler.enabledRuntimeType = true;
+        backend.registerRuntimeType(
+            compiler.enqueuer.resolution, compiler.globalDependencies);
+        return compiler;
+      });
     });
   } else {
     for (final task in compiler.tasks) {
diff --git a/pkg/dart2js_incremental/lib/dart2js_incremental.dart b/pkg/dart2js_incremental/lib/dart2js_incremental.dart
index a03829defa9..1ce8039c6b6 100644
--- a/pkg/dart2js_incremental/lib/dart2js_incremental.dart
+++ b/pkg/dart2js_incremental/lib/dart2js_incremental.dart
@@ -124,7 +124,7 @@ class IncrementalCompiler {
     }
     Future mappingInputProvider(Uri uri) {
       Uri updatedFile = updatedFiles[uri];
-      return inputProvider(updatedFile == null ? uri : updatedFile);
+      return inputProvider.readFromUri(updatedFile == null ? uri : updatedFile);
     }
     LibraryUpdater updater = new LibraryUpdater(
         _compiler,
@@ -134,7 +134,7 @@ class IncrementalCompiler {
         _context);
     _context.registerUriWithUpdates(updatedFiles.keys);
     Future<CompilerImpl> future = _reuseCompiler(updater.reuseLibrary);
-    return future.then((Compiler compiler) {
+    return future.then((CompilerImpl compiler) {
       _compiler = compiler;
       if (compiler.compilationFailed) {
         return null;
@@ -157,9 +157,7 @@ function dartMainRunner(main, args) {
   return main(args);
 }""", {'updates': updates, 'helper': backend.namer.accessIncrementalHelper});
 
-    jsAst.Printer printer = new jsAst.Printer(_compiler, null);
-    printer.blockOutWithoutBraces(mainRunner);
-    return printer.outBuffer.getText();
+    return jsAst.prettyPrint(mainRunner, _compiler).getText();
   }
 }
 
diff --git a/sdk/lib/dart2dart.platform b/sdk/lib/dart2dart.platform
new file mode 100644
index 00000000000..fd9d8ed0d9d
--- /dev/null
+++ b/sdk/lib/dart2dart.platform
@@ -0,0 +1,48 @@
+# Copyright (c) 2015, 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.
+
+# The platform when compiling with dart2js for dart2dart.
+#
+# Includes the _mirror_helpers private libraries
+
+[dart-spec]
+spec:3rd edition.
+
+[features]
+# No extra features.
+
+[libraries]
+async: async/async.dart
+_chrome: _chrome/dart2js/chrome_dart2js.dart
+collection: collection/collection.dart
+convert: convert/convert.dart
+core: core/core.dart
+developer: developer/developer.dart
+html: html/dart2js/html_dart2js.dart
+html_common: html/html_common/html_common_dart2js.dart
+indexed_db: indexed_db/dart2js/indexed_db_dart2js.dart
+io: io/io.dart
+isolate: isolate/isolate.dart
+js: js/dart2js/js_dart2js.dart
+math: math/math.dart
+mirrors: mirrors/mirrors.dart
+nativewrappers: html/dart2js/nativewrappers.dart
+typed_data: typed_data/typed_data.dart
+_native_typed_data: _internal/js_runtime/lib/native_typed_data.dart
+svg: svg/dart2js/svg_dart2js.dart
+web_audio: web_audio/dart2js/web_audio_dart2js.dart
+web_gl: web_gl/dart2js/web_gl_dart2js.dart
+web_sql: web_sql/dart2js/web_sql_dart2js.dart
+_internal: internal/internal.dart
+_js_helper: _internal/js_runtime/lib/js_helper.dart
+_interceptors: _internal/js_runtime/lib/interceptors.dart
+_foreign_helper: _internal/js_runtime/lib/foreign_helper.dart
+_isolate_helper: _internal/js_runtime/lib/isolate_helper.dart
+_js_mirrors: _internal/js_runtime/lib/js_mirrors.dart
+_js_names: _internal/js_runtime/lib/js_names.dart
+_js_primitives: _internal/js_runtime/lib/js_primitives.dart
+_mirror_helper: _internal/js_runtime/lib/mirror_helper.dart
+_js_embedded_names: _internal/js_runtime/lib/shared/embedded_names.dart
+_async_await_error_codes: _internal/js_runtime/lib/shared/async_await_error_codes.dart
+_metadata: html/html_common/metadata.dart
diff --git a/sdk/lib/dart_client.platform b/sdk/lib/dart_client.platform
new file mode 100644
index 00000000000..2e01cd991bc
--- /dev/null
+++ b/sdk/lib/dart_client.platform
@@ -0,0 +1,49 @@
+# Copyright (c) 2015, 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.
+
+# The platform for running dart on the web with dart2js.
+#
+# Includes dart:html and associated libraries.
+# Does not include dart:io.
+
+[dart-spec]
+spec: 3rd edition.
+
+[features]
+# No extra features.
+
+[libraries]
+async: async/async.dart
+_chrome: _chrome/dart2js/chrome_dart2js.dart
+collection: collection/collection.dart
+convert: convert/convert.dart
+core: core/core.dart
+developer: developer/developer.dart
+html: html/dart2js/html_dart2js.dart
+html_common: html/html_common/html_common_dart2js.dart
+indexed_db: indexed_db/dart2js/indexed_db_dart2js.dart
+io: unsupported:
+isolate: isolate/isolate.dart
+js: js/dart2js/js_dart2js.dart
+math: math/math.dart
+mirrors: mirrors/mirrors.dart
+nativewrappers: html/dart2js/nativewrappers.dart
+typed_data: typed_data/typed_data.dart
+_native_typed_data: _internal/js_runtime/lib/native_typed_data.dart
+svg: svg/dart2js/svg_dart2js.dart
+web_audio: web_audio/dart2js/web_audio_dart2js.dart
+web_gl: web_gl/dart2js/web_gl_dart2js.dart
+web_sql: web_sql/dart2js/web_sql_dart2js.dart
+_internal: internal/internal.dart
+_js_helper: _internal/js_runtime/lib/js_helper.dart
+_interceptors: _internal/js_runtime/lib/interceptors.dart
+_foreign_helper: _internal/js_runtime/lib/foreign_helper.dart
+_isolate_helper: _internal/js_runtime/lib/isolate_helper.dart
+_js_mirrors: _internal/js_runtime/lib/js_mirrors.dart
+_js_names: _internal/js_runtime/lib/js_names.dart
+_js_primitives: _internal/js_runtime/lib/js_primitives.dart
+_js_embedded_names: _internal/js_runtime/lib/shared/embedded_names.dart
+_async_await_error_codes: _internal/js_runtime/lib/shared/async_await_error_codes.dart
+_metadata: html/html_common/metadata.dart
+_mirror_helper: unsupported:
diff --git a/sdk/lib/dart_server.platform b/sdk/lib/dart_server.platform
new file mode 100644
index 00000000000..821a1753ac6
--- /dev/null
+++ b/sdk/lib/dart_server.platform
@@ -0,0 +1,49 @@
+# Copyright (c) 2015, 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.
+
+# The platform for dart on the server with dart2js.
+#
+# Includes dart:io.
+# Does not include dart:html and associated libraries.
+
+[dart-spec]
+spec:3rd edition.
+
+[features]
+# No extra features.
+
+[libraries]
+async: async/async.dart
+collection: collection/collection.dart
+convert: convert/convert.dart
+core: core/core.dart
+developer: developer/developer.dart
+io: io/io.dart
+isolate: isolate/isolate.dart
+math: math/math.dart
+mirrors: mirrors/mirrors.dart
+nativewrappers: html/dart2js/nativewrappers.dart
+typed_data: typed_data/typed_data.dart
+_native_typed_data: _internal/js_runtime/lib/native_typed_data.dart
+html: unsupported:
+html_common: unsupported:
+indexed_db: unsupported:
+svg: unsupported:
+web_audio: unsupported:
+web_gl: unsupported:
+web_sql: unsupported:
+_chrome: unsupported:
+js: unsupported:
+_mirror_helper: unsupported:
+_internal: internal/internal.dart
+_js_helper: _internal/js_runtime/lib/js_helper.dart
+_interceptors: _internal/js_runtime/lib/interceptors.dart
+_foreign_helper: _internal/js_runtime/lib/foreign_helper.dart
+_isolate_helper: _internal/js_runtime/lib/isolate_helper.dart
+_js_mirrors: _internal/js_runtime/lib/js_mirrors.dart
+_js_names: _internal/js_runtime/lib/js_names.dart
+_js_primitives: _internal/js_runtime/lib/js_primitives.dart
+_js_embedded_names: _internal/js_runtime/lib/shared/embedded_names.dart
+_async_await_error_codes: _internal/js_runtime/lib/shared/async_await_error_codes.dart
+_metadata: html/html_common/metadata.dart
diff --git a/sdk/lib/dart_shared.platform b/sdk/lib/dart_shared.platform
new file mode 100644
index 00000000000..539b8688966
--- /dev/null
+++ b/sdk/lib/dart_shared.platform
@@ -0,0 +1,47 @@
+# Copyright (c) 2015, 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.
+
+# A combination of the libraries for dart on the server and client.
+# For testing purposes only.
+
+[dart-spec]
+spec:3rd edition.
+
+[features]
+# No extra features.
+
+[libraries]
+async: async/async.dart
+_chrome: _chrome/dart2js/chrome_dart2js.dart
+collection: collection/collection.dart
+convert: convert/convert.dart
+core: core/core.dart
+developer: developer/developer.dart
+html: html/dart2js/html_dart2js.dart
+html_common: html/html_common/html_common_dart2js.dart
+indexed_db: indexed_db/dart2js/indexed_db_dart2js.dart
+io: io/io.dart
+isolate: isolate/isolate.dart
+js: js/dart2js/js_dart2js.dart
+math: math/math.dart
+mirrors: mirrors/mirrors.dart
+nativewrappers: html/dart2js/nativewrappers.dart
+typed_data: typed_data/typed_data.dart
+_native_typed_data: _internal/js_runtime/lib/native_typed_data.dart
+svg: svg/dart2js/svg_dart2js.dart
+web_audio: web_audio/dart2js/web_audio_dart2js.dart
+web_gl: web_gl/dart2js/web_gl_dart2js.dart
+web_sql: web_sql/dart2js/web_sql_dart2js.dart
+_internal: internal/internal.dart
+_js_helper: _internal/js_runtime/lib/js_helper.dart
+_interceptors: _internal/js_runtime/lib/interceptors.dart
+_foreign_helper: _internal/js_runtime/lib/foreign_helper.dart
+_isolate_helper: _internal/js_runtime/lib/isolate_helper.dart
+_js_mirrors: _internal/js_runtime/lib/js_mirrors.dart
+_js_names: _internal/js_runtime/lib/js_names.dart
+_js_primitives: _internal/js_runtime/lib/js_primitives.dart
+_js_embedded_names: _internal/js_runtime/lib/shared/embedded_names.dart
+_async_await_error_codes: _internal/js_runtime/lib/shared/async_await_error_codes.dart
+_metadata: html/html_common/metadata.dart
+_mirror_helper: unsupported:
diff --git a/tests/compiler/dart2js/analyze_only_test.dart b/tests/compiler/dart2js/analyze_only_test.dart
index 08100a62d39..2d771fb5349 100644
--- a/tests/compiler/dart2js/analyze_only_test.dart
+++ b/tests/compiler/dart2js/analyze_only_test.dart
@@ -49,8 +49,8 @@ runCompiler(String main, List<String> options,
               localProvider, localHandler, options, outputCollector);
   result.then((_) {
     onValue(outputCollector.getOutput('', 'js'), errors, warnings);
-  }, onError: (e) {
-    throw 'Compilation failed: ${Error.safeToString(e)}';
+  }, onError: (e, st) {
+    throw 'Compilation failed: ${e} ${st}';
   }).then(asyncSuccess).catchError((error, stack) {
     print('\n\n-----------------------------------------------');
     print('main source:\n$main');
diff --git a/tests/compiler/dart2js/backend_dart/dart_backend_test.dart b/tests/compiler/dart2js/backend_dart/dart_backend_test.dart
index 597f056807c..5db41609dec 100644
--- a/tests/compiler/dart2js/backend_dart/dart_backend_test.dart
+++ b/tests/compiler/dart2js/backend_dart/dart_backend_test.dart
@@ -4,6 +4,7 @@
 
 import "package:expect/expect.dart";
 import 'dart:async';
+import 'dart:io' as io;
 import "package:async_helper/async_helper.dart";
 import '../mock_compiler.dart';
 import '../mock_libraries.dart';
@@ -58,7 +59,9 @@ testDart2Dart(String mainSrc, {String librarySrc,
     if (uri.toString() == libUri.toString()) {
       return new Future.value(librarySrc);
     }
-    if (uri.path.endsWith('/core.dart')) {
+    if (uri.path.endsWith('/dart2dart.platform')) {
+      return new io.File.fromUri(uri).readAsBytes();
+    } else if (uri.path.endsWith('/core.dart')) {
       return new Future.value(buildLibrarySource(DEFAULT_CORE_LIBRARY));
     } else if (uri.path.endsWith('/core_patch.dart')) {
       return new Future.value(DEFAULT_PATCH_CORE_SOURCE);
@@ -87,7 +90,6 @@ testDart2Dart(String mainSrc, {String librarySrc,
 
   final options = <String>['--output-type=dart'];
   // Some tests below are using dart:io.
-  options.add('--categories=Client,Server');
   if (minify) options.add('--minify');
   if (stripTypes) options.add('--force-strip=types');
 
@@ -95,7 +97,7 @@ testDart2Dart(String mainSrc, {String librarySrc,
     OutputCollector outputCollector = new OutputCollector();
     return compile(
         scriptUri,
-        fileUri('libraryRoot/'),
+        Uri.base.resolve('sdk/'),
         fileUri('packageRoot/'),
         provider,
         handler,
diff --git a/tests/compiler/dart2js/categories_test.dart b/tests/compiler/dart2js/categories_test.dart
index 3b22453112c..677d1a83a60 100644
--- a/tests/compiler/dart2js/categories_test.dart
+++ b/tests/compiler/dart2js/categories_test.dart
@@ -19,17 +19,13 @@ runTest(String source, String categories, int expectedErrors) async {
 
 void main() {
   asyncTest(() async {
-    await runTest("import 'dart:async'; main() {}", "Embedded", 1);
     await runTest("import 'dart:async'; main() {}", "Client", 0);
     await runTest("import 'dart:async'; main() {}", "Server", 0);
-    await runTest("import 'dart:html'; main() {}", "Embedded", 1);
     await runTest("import 'dart:html'; main() {}", "Client", 0);
     await runTest("import 'dart:html'; main() {}", "Server", 1);
-    await runTest("import 'dart:io'; main() {}", "Embedded", 1);
     await runTest("import 'dart:io'; main() {}", "Client", 1);
     await runTest("import 'dart:io'; main() {}", "Server", 0);
-    await runTest("import 'dart:_internal'; main() {}", "Embedded", 2);
-    await runTest("import 'dart:_internal'; main() {}", "Client", 2);
-    await runTest("import 'dart:_internal'; main() {}", "Server", 2);
+    await runTest("import 'dart:_internal'; main() {}", "Client", 1);
+    await runTest("import 'dart:_internal'; main() {}", "Server", 1);
   });
 }
diff --git a/tests/compiler/dart2js/library_resolution_test.dart b/tests/compiler/dart2js/library_resolution_test.dart
index d45431236d5..28ad567248c 100644
--- a/tests/compiler/dart2js/library_resolution_test.dart
+++ b/tests/compiler/dart2js/library_resolution_test.dart
@@ -14,92 +14,58 @@ import "memory_source_file_helper.dart";
 
 import "package:async_helper/async_helper.dart";
 
-import 'package:expect/expect.dart' show
-    Expect;
+import 'package:expect/expect.dart' show Expect;
 
-import 'package:compiler/src/diagnostics/messages.dart' show
-    MessageKind,
-    MessageTemplate;
+import 'package:compiler/src/diagnostics/messages.dart'
+    show MessageKind, MessageTemplate;
 
-import 'package:compiler/src/elements/elements.dart' show
-    LibraryElement;
+import 'package:compiler/src/elements/elements.dart' show LibraryElement;
 
-import 'package:compiler/src/null_compiler_output.dart' show
-    NullCompilerOutput;
+import 'package:compiler/src/null_compiler_output.dart' show NullCompilerOutput;
 
-import 'package:compiler/src/old_to_new_api.dart' show
-    LegacyCompilerDiagnostics,
-    LegacyCompilerInput;
-
-import 'package:sdk_library_metadata/libraries.dart' show
-    DART2JS_PLATFORM,
-    LibraryInfo;
-
-const LibraryInfo mock1LibraryInfo = const LibraryInfo(
-    "mock1.dart",
-    categories: "Client,Embedded",
-    documented: false,
-    platforms: DART2JS_PLATFORM);
-
-const LibraryInfo mock2LibraryInfo = const LibraryInfo(
-    "mock2.dart",
-    categories: "Client,Embedded",
-    documented: false,
-    platforms: DART2JS_PLATFORM);
+import 'package:compiler/src/old_to_new_api.dart'
+    show LegacyCompilerDiagnostics, LegacyCompilerInput;
 
+Uri sdkRoot = Uri.base.resolve("sdk/");
+Uri mock1LibraryUri = sdkRoot.resolve("lib/mock1.dart");
+Uri mock2LibraryUri = sdkRoot.resolve("lib/mock2.dart");
 
 class CustomCompiler extends CompilerImpl {
-  final Map<String, LibraryInfo> customLibraryInfo;
+  CustomCompiler(provider, handler, libraryRoot,
+      packageRoot, options, environment)
+      : super(provider, const NullCompilerOutput(), handler, libraryRoot,
+            packageRoot, options, environment);
 
-  CustomCompiler(
-      this.customLibraryInfo,
-      provider,
-      handler,
-      libraryRoot,
-      packageRoot,
-      options,
-      environment)
-      : super(
-          provider,
-          const NullCompilerOutput(),
-          handler,
-          libraryRoot,
-          packageRoot,
-          options,
-          environment);
-
-  LibraryInfo lookupLibraryInfo(String name) {
-    if (name == "m_o_c_k_1") return mock1LibraryInfo;
-    if (name == "m_o_c_k_2") return mock2LibraryInfo;
-    return super.lookupLibraryInfo(name);
+  Uri lookupLibraryUri(String libraryName) {
+    if (libraryName == "m_o_c_k_1") return mock1LibraryUri;
+    if (libraryName == "m_o_c_k_2") return mock2LibraryUri;
+    return super.lookupLibraryUri(libraryName);
   }
 }
 
-main() {
-  Uri sdkRoot = Uri.base.resolve("sdk/");
+main() async {
   Uri packageRoot = Uri.base.resolve(Platform.packageRoot);
 
   var provider = new MemorySourceFileProvider(MEMORY_SOURCE_FILES);
   var handler = new FormattingDiagnosticHandler(provider);
 
   Future wrappedProvider(Uri uri) {
-    if (uri == sdkRoot.resolve('lib/mock1.dart')) {
+    if (uri == mock1LibraryUri) {
       return provider.readStringFromUri(Uri.parse('memory:mock1.dart'));
     }
-    if (uri == sdkRoot.resolve('lib/mock2.dart')) {
+    if (uri == mock2LibraryUri) {
       return provider.readStringFromUri(Uri.parse('memory:mock2.dart'));
     }
     return provider.readStringFromUri(uri);
   }
 
-  String expectedMessage =
-      MessageTemplate.TEMPLATES[MessageKind.LIBRARY_NOT_FOUND].message(
-          {'resolvedUri': 'dart:mock2.dart'}).computeMessage();
+  String expectedMessage = MessageTemplate.TEMPLATES[
+          MessageKind.LIBRARY_NOT_FOUND]
+      .message({'resolvedUri': 'dart:mock2.dart'}).computeMessage();
 
   int actualMessageCount = 0;
 
-  wrappedHandler(
-      Uri uri, int begin, int end, String message, kind) {
+  wrappedHandler(Uri uri, int begin, int end, String message, kind) {
     if (message == expectedMessage) {
       actualMessageCount++;
     } else {
@@ -112,7 +78,6 @@ main() {
   }
 
   CompilerImpl compiler = new CustomCompiler(
-      {},
       new LegacyCompilerInput(wrappedProvider),
       new LegacyCompilerDiagnostics(wrappedHandler),
       sdkRoot,
@@ -121,9 +86,11 @@ main() {
       {});
 
   asyncStart();
-  compiler.libraryLoader.loadLibrary(Uri.parse("dart:m_o_c_k_1"))
-      .then(checkLibrary)
-      .then(asyncSuccess);
+  await compiler.setupSdk();
+  var library =
+      await compiler.libraryLoader.loadLibrary(Uri.parse("dart:m_o_c_k_1"));
+  await checkLibrary(library);
+  asyncSuccess(null);
 }
 
 const Map MEMORY_SOURCE_FILES = const {
diff --git a/tests/compiler/dart2js/mock_libraries.dart b/tests/compiler/dart2js/mock_libraries.dart
index 37135b2274d..e73586c0cc0 100644
--- a/tests/compiler/dart2js/mock_libraries.dart
+++ b/tests/compiler/dart2js/mock_libraries.dart
@@ -6,6 +6,15 @@
 
 library mock_libraries;
 
+const DEFAULT_PLATFORM_CONFIG = """
+[libraries]
+core:core/core.dart
+async:async/async.dart
+_js_helper:_internal/js_runtime/lib/js_helper.dart
+_interceptors:_internal/js_runtime/lib/interceptors.dart
+_isolate_helper:_internal/js_runtime/lib/isolate_helper.dart
+""";
+
 String buildLibrarySource(
     Map<String, String> elementMap,
     [Map<String, String> additionalElementMap = const <String, String>{}]) {
diff --git a/tests/compiler/dart2js/platform_config_parser_test.dart b/tests/compiler/dart2js/platform_config_parser_test.dart
new file mode 100644
index 00000000000..a25e2da1d6c
--- /dev/null
+++ b/tests/compiler/dart2js/platform_config_parser_test.dart
@@ -0,0 +1,130 @@
+// Copyright (c) 2015, 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.
+
+import "package:compiler/src/platform_configuration.dart";
+import "package:expect/expect.dart";
+
+/// Runs the parser on [input] and compares it with [expectedResult]
+///
+/// A '*' in [input] indicates that the parser will report an error at the
+/// given point (On [input] with the "*" removed).
+test(String input, [Map<String, Map<String, String>> expectedOutput]) {
+  int starIndex = input.indexOf("*");
+  String inputWithoutStar = input.replaceFirst("*", "");
+
+  parse() => parseIni(inputWithoutStar.codeUnits,
+      allowedSections: new Set.from(["AA", "BB"]));
+
+  if (starIndex != -1) {
+    Expect.equals(expectedOutput, null);
+    Expect.throws(parse, (e) {
+      Expect.isTrue(e is FormatException);
+      Expect.equals(starIndex, e.offset);
+      return e is FormatException;
+    });
+  } else {
+    Map<String, Map<String, String>> result = parse();
+    Expect.equals(expectedOutput.length, result.length);
+    expectedOutput.forEach((String name, Map<String, String> properties) {
+      Expect.isTrue(expectedOutput.containsKey(name), "Missing section $name");
+      Expect.mapEquals(expectedOutput[name], properties);
+    });
+  }
+}
+
+main() {
+  // Empty file.
+  test(
+      """
+# Nothing here
+""",
+      {});
+
+  // Text outside section.
+  test("""
+*aaa
+""");
+
+  // Malformed header.
+  test("""
+*[AABC
+name:value
+""");
+
+  // Text after header.
+  test("""
+[AABC]*abcde
+""");
+
+  // Empty section name.
+  test("""
+[*]
+""");
+
+  // Duplicate section name.
+  test("""
+[AA]
+[BB]
+[*AA]
+""");
+
+  // Unrecognized section name.
+  test("""
+[*CC]
+""");
+
+  // Empty property name.
+  test("""
+[AA]
+*:value
+name:value
+""");
+
+  // Ok.
+  test(
+      """
+[AA]
+name:value
+[BB]
+name:value
+name2:value2
+""",
+      {
+    "AA": {"name": "value"},
+    "BB": {"name": "value", "name2": "value2"}
+  });
+
+  // Ok, file not ending in newline.
+  test(
+      """
+[AA]
+name:value""",
+      {
+    "A": {"name": "value"}
+  });
+
+  // Ok, whitespace is trimmed away.
+  test(
+      """
+[ AA ]
+ name\t:  value """,
+      {
+        "A": {"name": "value"}
+      });
+
+  // Duplicate property name.
+  test("""
+[AA]
+a:b
+b:c
+*a:c
+""");
+
+  // No ':' on property line.
+  test("""
+[AA]
+*name1
+name2:value
+""");
+}
diff --git a/tests/compiler/dart2js/platform_consistency_test.dart b/tests/compiler/dart2js/platform_consistency_test.dart
new file mode 100644
index 00000000000..e946c167e29
--- /dev/null
+++ b/tests/compiler/dart2js/platform_consistency_test.dart
@@ -0,0 +1,41 @@
+// Copyright (c) 2015, the Fletch 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.md file.
+
+import "package:compiler/src/platform_configuration.dart";
+import "package:compiler/src/source_file_provider.dart";
+import "package:compiler/compiler_new.dart";
+import "package:expect/expect.dart";
+
+Uri unsupported =  Uri.parse("unsupported:");
+
+main() async {
+  CompilerInput input = new CompilerSourceFileProvider();
+  Map<String, Uri> client = await load(
+      Uri.base.resolve("sdk/lib/dart_client.platform"),
+      input);
+  Map<String, Uri> server = await load(
+      Uri.base.resolve("sdk/lib/dart_server.platform"),
+      input);
+  Map<String, Uri> shared = await load(
+      Uri.base.resolve("sdk/lib/dart_shared.platform"),
+      input);
+  Map<String, Uri> dart2dart = await load(
+      Uri.base.resolve("sdk/lib/dart2dart.platform"),
+      input);
+  Expect.setEquals(new Set.from(shared.keys), new Set.from(client.keys));
+  Expect.setEquals(new Set.from(shared.keys), new Set.from(server.keys));
+  Expect.setEquals(new Set.from(shared.keys), new Set.from(dart2dart.keys));
+
+  for (String libraryName in shared.keys) {
+    test(Map<String, Uri> m) {
+      if (m[libraryName] != unsupported &&
+          shared[libraryName] != unsupported) {
+        Expect.equals(shared[libraryName], m[libraryName]);
+      }
+    }
+    test(client);
+    test(server);
+    test(dart2dart);
+  }
+ }
diff --git a/tests/utils/dummy_compiler_test.dart b/tests/utils/dummy_compiler_test.dart
index 43a79c58c51..608e0996686 100644
--- a/tests/utils/dummy_compiler_test.dart
+++ b/tests/utils/dummy_compiler_test.dart
@@ -15,7 +15,9 @@ import 'package:compiler/compiler.dart';
 import '../compiler/dart2js/mock_libraries.dart';
 
 String libProvider(Uri uri) {
-  if (uri.path.endsWith("/core.dart")) {
+  if (uri.path.endsWith(".platform")) {
+    return DEFAULT_PLATFORM_CONFIG;
+  } if (uri.path.endsWith("/core.dart")) {
     return buildLibrarySource(DEFAULT_CORE_LIBRARY);
   } else if (uri.path.endsWith('core_patch.dart')) {
     return DEFAULT_PATCH_CORE_SOURCE;
diff --git a/tools/create_sdk.py b/tools/create_sdk.py
index bdb69f237ef..11ff386ae83 100755
--- a/tools/create_sdk.py
+++ b/tools/create_sdk.py
@@ -39,6 +39,10 @@
 # ......dart_native_api.h
 # ......dart_tools_api.h
 # ....lib/
+# ......dart_client.platform
+# ......dart_server.platform
+# ......dart_shared.platform
+# ......dart2dart.platform
 # ......_internal/
 # ......async/
 # ......collection/
@@ -241,6 +245,13 @@ def Main():
              ignore=ignore_patterns('*.svn', 'doc', '*.py', '*.gypi', '*.sh',
                                     '.gitignore'))
 
+  # Copy the platform descriptors.
+  for file_name in ["dart_client.platform",
+                    "dart_server.platform",
+                    "dart_shared.platform",
+                    "dart2dart.platform"]:
+    copyfile(join(HOME, 'sdk', 'lib', file_name), join(LIB, file_name));
+
   # Copy libraries.dart to lib/_internal/libraries.dart for backwards
   # compatibility.
   #