diff --git a/examples/fitness/lib/main.dart b/examples/fitness/lib/main.dart
index a4d40d1b2ac9282b4f335c672e9ac0a5e508c311..740ac9e79cfbcc0036a9611c2b79775d639a2518 100644
--- a/examples/fitness/lib/main.dart
+++ b/examples/fitness/lib/main.dart
@@ -5,6 +5,7 @@
 library fitness;
 
 import 'package:playfair/playfair.dart' as playfair;
+import 'package:sky/animation.dart';
 import 'package:sky/painting/text_style.dart';
 import 'package:sky/theme/colors.dart' as colors;
 import 'package:sky/widgets.dart';
diff --git a/examples/rendering/spinning_flex.dart b/examples/rendering/spinning_flex.dart
index d217c325a6084536eaeec63a2e4daa5235c4114d..b2fc6e894f8ec3ba3f40969f525b2c5523cbd97d 100644
--- a/examples/rendering/spinning_flex.dart
+++ b/examples/rendering/spinning_flex.dart
@@ -4,7 +4,7 @@
 
 import 'dart:sky' as sky;
 
-import 'package:sky/base/scheduler.dart' as scheduler;
+import 'package:sky/animation.dart';
 import 'package:sky/rendering.dart';
 
 import 'solid_color_box.dart';
diff --git a/examples/stocks/lib/main.dart b/examples/stocks/lib/main.dart
index ba81c856ac6c48ddb6164c41ad0c7ca8a46082db..1962baa424ff9d4184ef7402cd9c5a13950d795f 100644
--- a/examples/stocks/lib/main.dart
+++ b/examples/stocks/lib/main.dart
@@ -9,6 +9,7 @@ import 'dart:sky' as sky;
 
 import 'package:sky/theme/colors.dart' as colors;
 import 'package:sky/theme/typography.dart' as typography;
+import 'package:sky/animation.dart';
 import 'package:sky/widgets.dart';
 
 import 'stock_data.dart';
diff --git a/examples/widgets/card_collection.dart b/examples/widgets/card_collection.dart
index b81da2807c5523e4b542e7f42f88fd5e8e17ed50..a0bbb3cd03d485e4baab6272db6a80f4262b56d7 100644
--- a/examples/widgets/card_collection.dart
+++ b/examples/widgets/card_collection.dart
@@ -4,6 +4,7 @@
 
 import 'package:sky/theme/colors.dart' as colors;
 import 'package:sky/theme/typography.dart' as typography;
+import 'package:sky/animation.dart';
 import 'package:sky/widgets.dart';
 
 class CardModel {
diff --git a/examples/widgets/pageable_list.dart b/examples/widgets/pageable_list.dart
index 881cff510714b30d247ce1ec07298f470ae2a0e8..a62630698afe0b40b30b73fbc711f84d1b87c70c 100644
--- a/examples/widgets/pageable_list.dart
+++ b/examples/widgets/pageable_list.dart
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'package:sky/theme/colors.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/widgets.dart';
 
 class CardModel {
diff --git a/examples/widgets/progress_indicator.dart b/examples/widgets/progress_indicator.dart
index a9be0488044ff25cfe73c188a5ba0eaf6ca0f275..1adc5dd22858814a4253f7a62d4979ac8c37b879 100644
--- a/examples/widgets/progress_indicator.dart
+++ b/examples/widgets/progress_indicator.dart
@@ -2,9 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:sky/animation/animation_performance.dart';
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/curves.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/theme/colors.dart' as colors;
 import 'package:sky/widgets.dart';
 
diff --git a/examples/widgets/spinning_mixed.dart b/examples/widgets/spinning_mixed.dart
index 44a20b37532d5708950379f06acc152e421b21ea..2a2463bf55ad09b91ad4bdd2d8d586b00eb533f7 100644
--- a/examples/widgets/spinning_mixed.dart
+++ b/examples/widgets/spinning_mixed.dart
@@ -4,7 +4,7 @@
 
 import 'dart:sky' as sky;
 
-import 'package:sky/base/scheduler.dart' as scheduler;
+import 'package:sky/animation.dart';
 import 'package:sky/rendering.dart';
 import 'package:sky/widgets.dart';
 
diff --git a/sky/packages/sky/lib/README.md b/sky/packages/sky/lib/README.md
index c52ef87186dacaf0baf682564671a6d4b9a09b5a..1b27173276c67f29b3cacdee7f4369ee27e3b66c 100644
--- a/sky/packages/sky/lib/README.md
+++ b/sky/packages/sky/lib/README.md
@@ -5,31 +5,30 @@ Sky and Sky's SDK are designed as layered frameworks, where each layer
 depends on the ones below it but could be replaced wholesale.
 
 The bottom-most layer is the Sky Platform, which is exposed to Dart
-code as [various ```dart:``` packages](https://api.dartlang.org/),
-including ```dart:sky```.
+code as [various `dart:` packages](https://api.dartlang.org/),
+including `dart:sky`.
 
 The [base/](base/) directory contains libraries that extend these core
 APIs to provide base classes for tree structures
 ([base/node.dart](base/node.dart)), hit testing
-([base/hit_test.dart](base/hit_test.dart)), debugging
-([base/debug.dart](base/debug.dart)), and task scheduling
-([base/scheduler.dart](base/scheduler.dart)).
+([base/hit_test.dart](base/hit_test.dart)), and debugging
+([base/debug.dart](base/debug.dart)).
 
-Above this are the files in the [animation/](animation/) directory,
-which provide core primitives for animating values, and in the [gestures/](gestures/)
+Above this layer is the [animation](animation.dart) library,
+which provides core animation primitives, and the [gestures/](gestures/)
 directory, which define a gesture recognition and disambiguation system.
 
 The next layer consists of the files in the [painting/](painting/) directory,
 which provide APIs related to drawing graphics. Some of the code here
-uses the [animation/](animation/) utilities mentioned above.
+uses the [animation](animation.dart) utilities mentioned above.
 
 Layout primitives are provided in the next layer, found in the
-[rendering/](rendering/) directory. They use ```dart:sky``` and the
-APIs exposed in painting/ to provide a retained-mode layout and
+[rendering](rendering.dart) library. They use `dart:sky` and the
+APIs exposed in [painting/](painting/) to provide a retained-mode layout and
 rendering model for applications or documents.
 
-Widgets are provided by the files in the [widgets/](widgets/)
-directory, using a reactive framework. They use data given in the
+Widgets are provided by the files in the [widgets](widgets.dart)
+library, using a reactive framework. They use data given in the
 [theme/](theme/) directory to select styles consistent with Material
 Design.
 
@@ -38,18 +37,18 @@ anything that uses the Mojo IPC mechanism, typically as part of
 wrapping host operating system features. Some of those Host APIs are
 implemented in the host system's preferred language.
 
-Here is a diagram summarising all this:
+Here is a diagram summarizing all this:
 
     +-----------------------------+ ------
     |           YOUR APP          |
     |  +----------------------+---+
-    |  |  widgets/  (theme/)  |   |
+    |  |  widgets   (theme/)  |   |
     | ++---------------------++   |
-    | |      rendering/      |    |  Dart
+    | |      rendering       |    |  Dart
     | |---------+------------+    |
     | |         | painting/  |    |
     +-+         +------------+    |
-    | gestures/ | animation/ |    |
+    | gestures/ | animation  |    |
     +-----------+---+--------+    |
     |    base/      |  mojo/      |
     +------------+--+-+----+------+ -------
diff --git a/sky/packages/sky/lib/animation.dart b/sky/packages/sky/lib/animation.dart
new file mode 100644
index 0000000000000000000000000000000000000000..6a8b2869b2016bc266b5cd69e3a61d40112cbb53
--- /dev/null
+++ b/sky/packages/sky/lib/animation.dart
@@ -0,0 +1,19 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/// The Sky animation engine.
+///
+/// This library includes and re-exports all Sky animation classes.
+library animation;
+
+export 'package:sky/src/rendering/auto_layout.dart';
+
+export 'src/animation/animated_simulation.dart';
+export 'src/animation/animated_value.dart';
+export 'src/animation/animation_performance.dart';
+export 'src/animation/curves.dart';
+export 'src/animation/forces.dart';
+export 'src/animation/scheduler.dart';
+export 'src/animation/scroll_behavior.dart';
+export 'src/animation/timeline.dart';
diff --git a/sky/packages/sky/lib/animation/direction.dart b/sky/packages/sky/lib/animation/direction.dart
deleted file mode 100644
index 1a72ed771f90c9b596ce7a24c27272cf383cde6f..0000000000000000000000000000000000000000
--- a/sky/packages/sky/lib/animation/direction.dart
+++ /dev/null
@@ -1,8 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-enum Direction {
-  forward,
-  reverse
-}
diff --git a/sky/packages/sky/lib/base/debug.dart b/sky/packages/sky/lib/base/debug.dart
index ae396dfd4927a82409bc5b2fe3559e026ad9e974..53e02ae9d919851cd1f1c73a3e47e4d846c6e83b 100644
--- a/sky/packages/sky/lib/base/debug.dart
+++ b/sky/packages/sky/lib/base/debug.dart
@@ -40,6 +40,3 @@ const sky.Color debugPaintLayerBordersColor = const sky.Color(0xFFFF9800);
 
 /// Causes RenderObjects to paint warnings when painting outside their bounds.
 bool debugPaintBoundsEnabled = false;
-
-/// Slows down animations by this factor to help in development.
-double timeDilation = 1.0;
diff --git a/sky/packages/sky/lib/base/scheduler.dart b/sky/packages/sky/lib/base/scheduler.dart
deleted file mode 100644
index c0e0ecea8a887b3836d205a518507448b02a3368..0000000000000000000000000000000000000000
--- a/sky/packages/sky/lib/base/scheduler.dart
+++ /dev/null
@@ -1,88 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-import 'dart:collection';
-import 'dart:sky' as sky;
-
-import 'package:sky/base/debug.dart';
-
-/// A callback from the scheduler
-///
-/// The timeStamp is the number of milliseconds since the beginning of the
-/// scheduler's epoch. Use timeStamp to determine how far to advance animation
-/// timelines so that all the animations in the system are synchronized to a
-/// common time base.
-typedef void SchedulerCallback(double timeStamp);
-
-bool _haveScheduledVisualUpdate = false;
-int _nextCallbackId = 1;
-
-final List<SchedulerCallback> _persistentCallbacks = new List<SchedulerCallback>();
-Map<int, SchedulerCallback> _transientCallbacks = new LinkedHashMap<int, SchedulerCallback>();
-final Set<int> _removedIds = new Set<int>();
-
-/// Called by the engine to produce a new frame.
-///
-/// This function first calls all the callbacks registered by
-/// [requestAnimationFrame] and then calls all the callbacks registered by
-/// [addPersistentFrameCallback], which typically drive the rendering pipeline.
-void beginFrame(double timeStamp) {
-  timeStamp /= timeDilation;
-
-  _haveScheduledVisualUpdate = false;
-
-  Map<int, SchedulerCallback> callbacks = _transientCallbacks;
-  _transientCallbacks = new Map<int, SchedulerCallback>();
-
-  callbacks.forEach((id, callback) {
-    if (!_removedIds.contains(id))
-      callback(timeStamp);
-  });
-  _removedIds.clear();
-
-  for (SchedulerCallback callback in _persistentCallbacks)
-    callback(timeStamp);
-}
-
-/// Registers [beginFrame] callback with the engine.
-void init() {
-  sky.view.setFrameCallback(beginFrame);
-}
-
-/// Call callback every frame.
-void addPersistentFrameCallback(SchedulerCallback callback) {
-  _persistentCallbacks.add(callback);
-}
-
-/// Schedule a callback for the next frame.
-///
-/// The callback will be run prior to flushing the main rendering pipeline.
-/// Typically, requestAnimationFrame is used to throttle writes into the
-/// rendering pipeline until the system is ready to accept a new frame. For
-/// example, if you wanted to tick through an animation, you should use
-/// requestAnimation frame to determine when to tick the animation. The callback
-/// is passed a timeStamp that you can use to determine how far along the
-/// timeline to advance your animation.
-///
-/// Returns an id that can be used to unschedule this callback.
-int requestAnimationFrame(SchedulerCallback callback) {
-  int id = _nextCallbackId++;
-  _transientCallbacks[id] = callback;
-  ensureVisualUpdate();
-  return id;
-}
-
-/// Cancel the callback identified by id.
-void cancelAnimationFrame(int id) {
-  _transientCallbacks.remove(id);
-  _removedIds.add(id);
-}
-
-/// Ensure that a frame will be produced after this function is called.
-void ensureVisualUpdate() {
-  if (_haveScheduledVisualUpdate)
-    return;
-  sky.view.scheduleFrame();
-  _haveScheduledVisualUpdate = true;
-}
diff --git a/sky/packages/sky/lib/painting/README.md b/sky/packages/sky/lib/painting/README.md
index 64967d7d8f024e1764aa57c844f010a03d79265c..ed05e995f643a96ea42c4863fb73389f0bad5341 100644
--- a/sky/packages/sky/lib/painting/README.md
+++ b/sky/packages/sky/lib/painting/README.md
@@ -1,3 +1,3 @@
 This directory contains painting-related libraries that only depend on
-core Dart libraries, ../base/*, and ../animation/*. Note that
-../animation/* depends on the Newton Dart library also.
+core Dart libraries, `../base/*`, and [animation.dart](../animation.dart). Note
+that [animation.dart](../animation.dart) depends on the Newton Dart library.
diff --git a/sky/packages/sky/lib/painting/radial_reaction.dart b/sky/packages/sky/lib/painting/radial_reaction.dart
index 69663d00b1264905feecf903cad9dfaf30ee264a..0e4aa0034c9a0e4286f4bdc6a1f171023264a262 100644
--- a/sky/packages/sky/lib/painting/radial_reaction.dart
+++ b/sky/packages/sky/lib/painting/radial_reaction.dart
@@ -6,9 +6,7 @@ import 'dart:async';
 import 'dart:sky' as sky;
 import 'dart:sky' show Point, Offset, Color, Paint;
 
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/animation_performance.dart';
-import 'package:sky/animation/curves.dart';
+import 'package:sky/animation.dart';
 
 const Duration _kShowDuration = const Duration(milliseconds: 300);
 const Duration _kHideDuration = const Duration(milliseconds: 200);
diff --git a/sky/packages/sky/lib/animation/README.md b/sky/packages/sky/lib/src/animation/README.md
similarity index 51%
rename from sky/packages/sky/lib/animation/README.md
rename to sky/packages/sky/lib/src/animation/README.md
index 55f96cae9ef7ed1f26c83ff12fab37f37f856d5f..6b2ebb3a0aa411479cee7428310b0209a4a7c847 100644
--- a/sky/packages/sky/lib/animation/README.md
+++ b/sky/packages/sky/lib/src/animation/README.md
@@ -1,2 +1,2 @@
 This directory contains animation-related libraries that only depend
-on core Dart libraries, the Newton Dart library, and ../base/*.
+on core Dart libraries and the Newton Dart library.
diff --git a/sky/packages/sky/lib/animation/animated_simulation.dart b/sky/packages/sky/lib/src/animation/animated_simulation.dart
similarity index 97%
rename from sky/packages/sky/lib/animation/animated_simulation.dart
rename to sky/packages/sky/lib/src/animation/animated_simulation.dart
index b3278e20762448d2abe0abacd054e7e44aa6152b..18ce06fc88eb7231223419ca3c9246663a0c61c6 100644
--- a/sky/packages/sky/lib/animation/animated_simulation.dart
+++ b/sky/packages/sky/lib/src/animation/animated_simulation.dart
@@ -5,7 +5,7 @@
 import 'dart:async';
 
 import 'package:newton/newton.dart';
-import 'package:sky/base/scheduler.dart' as scheduler;
+import 'package:sky/src/animation/scheduler.dart';
 
 const double _kSecondsPerMillisecond = 1000.0;
 
diff --git a/sky/packages/sky/lib/animation/animated_value.dart b/sky/packages/sky/lib/src/animation/animated_value.dart
similarity index 94%
rename from sky/packages/sky/lib/animation/animated_value.dart
rename to sky/packages/sky/lib/src/animation/animated_value.dart
index 02cc3b3b8c39880025f6fcd748654ac65eb0edb2..7f9877d911c4da913aa869cce9a8d2836b7cbfc3 100644
--- a/sky/packages/sky/lib/animation/animated_value.dart
+++ b/sky/packages/sky/lib/src/animation/animated_value.dart
@@ -4,10 +4,12 @@
 
 import "dart:sky";
 
-import 'package:sky/animation/curves.dart';
-import 'package:sky/animation/direction.dart';
+import 'package:sky/src/animation/curves.dart';
 
-export 'package:sky/animation/curves.dart' show Interval;
+enum Direction {
+  forward,
+  reverse
+}
 
 abstract class AnimatedVariable {
   void setProgress(double t, Direction direction);
diff --git a/sky/packages/sky/lib/animation/animation_performance.dart b/sky/packages/sky/lib/src/animation/animation_performance.dart
similarity index 96%
rename from sky/packages/sky/lib/animation/animation_performance.dart
rename to sky/packages/sky/lib/src/animation/animation_performance.dart
index 700f572cdc3d2144fba6743475526c5d266b8919..af0c1744590e2cd3de4d2243a129f6dad9adb273 100644
--- a/sky/packages/sky/lib/animation/animation_performance.dart
+++ b/sky/packages/sky/lib/src/animation/animation_performance.dart
@@ -4,12 +4,9 @@
 
 import 'dart:async';
 
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/direction.dart';
-import 'package:sky/animation/forces.dart';
-import 'package:sky/animation/timeline.dart';
-
-export 'package:sky/animation/direction.dart' show Direction;
+import 'package:sky/src/animation/animated_value.dart';
+import 'package:sky/src/animation/forces.dart';
+import 'package:sky/src/animation/timeline.dart';
 
 enum AnimationStatus {
   dismissed, // stoped at 0
diff --git a/sky/packages/sky/lib/animation/curves.dart b/sky/packages/sky/lib/src/animation/curves.dart
similarity index 91%
rename from sky/packages/sky/lib/animation/curves.dart
rename to sky/packages/sky/lib/src/animation/curves.dart
index b16c1388e49c689e20881f77bdb66dc3a4ce0e28..5e9cb6892e1f3400cc8fd8c41761d35eb00cae60 100644
--- a/sky/packages/sky/lib/animation/curves.dart
+++ b/sky/packages/sky/lib/src/animation/curves.dart
@@ -39,22 +39,6 @@ class Interval implements Curve {
   }
 }
 
-class ParabolicFall implements Curve {
-  const ParabolicFall();
-
-  double transform(double t) {
-    return -t*t + 1;
-  }
-}
-
-class ParabolicRise implements Curve {
-  const ParabolicRise();
-
-  double transform(double t) {
-    return -(t-1)*(t-1) + 1;
-  }
-}
-
 class Cubic implements Curve {
   final double a;
   final double b;
@@ -162,8 +146,6 @@ const Cubic ease = const Cubic(0.25, 0.1, 0.25, 1.0);
 const Cubic easeIn = const Cubic(0.42, 0.0, 1.0, 1.0);
 const Cubic easeOut = const Cubic(0.0, 0.0, 0.58, 1.0);
 const Cubic easeInOut = const Cubic(0.42, 0.0, 0.58, 1.0);
-const ParabolicRise parabolicRise = const ParabolicRise();
-const ParabolicFall parabolicFall = const ParabolicFall();
 const BounceInCurve bounceIn = const BounceInCurve();
 const BounceOutCurve bounceOut = const BounceOutCurve();
 const BounceInOutCurve bounceInOut = const BounceInOutCurve();
diff --git a/sky/packages/sky/lib/animation/forces.dart b/sky/packages/sky/lib/src/animation/forces.dart
similarity index 87%
rename from sky/packages/sky/lib/animation/forces.dart
rename to sky/packages/sky/lib/src/animation/forces.dart
index 6353c8afc43de25dbdc3e31002026b9e5376686a..8c57978015fbfdf7195d2fd58fc81107285d5212 100644
--- a/sky/packages/sky/lib/animation/forces.dart
+++ b/sky/packages/sky/lib/src/animation/forces.dart
@@ -6,22 +6,25 @@ import 'package:newton/newton.dart';
 
 // Base class for creating Simulations for the animation Timeline.
 abstract class Force {
+  const Force();
+
   Simulation release(double position, double velocity);
 }
 
 class SpringForce extends Force {
-  SpringForce(this.spring, { this.left: 0.0, this.right: 1.0 });
+  const SpringForce(this.spring, { this.left: 0.0, this.right: 1.0 });
 
   final SpringDescription spring;
 
   // Where to put the spring's resting point when releasing left or right,
   // respectively.
-  final double left, right;
+  final double left;
+  final double right;
 
   // We overshoot the target by this distance, but stop the simulation when
   // the spring gets within this distance (regardless of how fast it's moving).
   // This causes the spring to settle a bit faster than it otherwise would.
-  static final Tolerance tolerance = new Tolerance(
+  static const Tolerance tolerance = const Tolerance(
     velocity: double.INFINITY,
     distance: 0.01
   );
diff --git a/sky/packages/sky/lib/src/animation/scheduler.dart b/sky/packages/sky/lib/src/animation/scheduler.dart
new file mode 100644
index 0000000000000000000000000000000000000000..999ba8900825c123aebef165ac54d1106ee760e5
--- /dev/null
+++ b/sky/packages/sky/lib/src/animation/scheduler.dart
@@ -0,0 +1,95 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:collection';
+import 'dart:sky' as sky;
+
+/// Slows down animations by this factor to help in development.
+double timeDilation = 1.0;
+
+/// A callback from the scheduler
+///
+/// The timeStamp is the number of milliseconds since the beginning of the
+/// scheduler's epoch. Use timeStamp to determine how far to advance animation
+/// timelines so that all the animations in the system are synchronized to a
+/// common time base.
+typedef void SchedulerCallback(double timeStamp);
+
+/// Schedules callbacks to run in concert with the engine's animation system
+class Scheduler {
+  /// Requires clients to use the [scheduler] singleton
+  Scheduler._() {
+    sky.view.setFrameCallback(beginFrame);
+  }
+
+  bool _haveScheduledVisualUpdate = false;
+  int _nextCallbackId = 1;
+
+  final List<SchedulerCallback> _persistentCallbacks = new List<SchedulerCallback>();
+  Map<int, SchedulerCallback> _transientCallbacks = new LinkedHashMap<int, SchedulerCallback>();
+  final Set<int> _removedIds = new Set<int>();
+
+  /// Called by the engine to produce a new frame.
+  ///
+  /// This function first calls all the callbacks registered by
+  /// [requestAnimationFrame] and then calls all the callbacks registered by
+  /// [addPersistentFrameCallback], which typically drive the rendering pipeline.
+  void beginFrame(double timeStamp) {
+    timeStamp /= timeDilation;
+
+    _haveScheduledVisualUpdate = false;
+
+    Map<int, SchedulerCallback> callbacks = _transientCallbacks;
+    _transientCallbacks = new Map<int, SchedulerCallback>();
+
+    callbacks.forEach((id, callback) {
+      if (!_removedIds.contains(id))
+        callback(timeStamp);
+    });
+    _removedIds.clear();
+
+    for (SchedulerCallback callback in _persistentCallbacks)
+      callback(timeStamp);
+  }
+
+  /// Call callback every frame.
+  void addPersistentFrameCallback(SchedulerCallback callback) {
+    _persistentCallbacks.add(callback);
+  }
+
+  /// Schedule a callback for the next frame.
+  ///
+  /// The callback will be run prior to flushing the main rendering pipeline.
+  /// Typically, requestAnimationFrame is used to throttle writes into the
+  /// rendering pipeline until the system is ready to accept a new frame. For
+  /// example, if you wanted to tick through an animation, you should use
+  /// requestAnimation frame to determine when to tick the animation. The callback
+  /// is passed a timeStamp that you can use to determine how far along the
+  /// timeline to advance your animation.
+  ///
+  /// Returns an id that can be used to unschedule this callback.
+  int requestAnimationFrame(SchedulerCallback callback) {
+    int id = _nextCallbackId++;
+    _transientCallbacks[id] = callback;
+    ensureVisualUpdate();
+    return id;
+  }
+
+  /// Cancel the callback identified by id.
+  void cancelAnimationFrame(int id) {
+    _transientCallbacks.remove(id);
+    _removedIds.add(id);
+  }
+
+  /// Ensure that a frame will be produced after this function is called.
+  void ensureVisualUpdate() {
+    if (_haveScheduledVisualUpdate)
+      return;
+    sky.view.scheduleFrame();
+    _haveScheduledVisualUpdate = true;
+  }
+}
+
+/// A singleton instance of Scheduler to coordinate all the callbacks.
+final Scheduler scheduler = new Scheduler._();
diff --git a/sky/packages/sky/lib/animation/scroll_behavior.dart b/sky/packages/sky/lib/src/animation/scroll_behavior.dart
similarity index 100%
rename from sky/packages/sky/lib/animation/scroll_behavior.dart
rename to sky/packages/sky/lib/src/animation/scroll_behavior.dart
diff --git a/sky/packages/sky/lib/animation/timeline.dart b/sky/packages/sky/lib/src/animation/timeline.dart
similarity index 97%
rename from sky/packages/sky/lib/animation/timeline.dart
rename to sky/packages/sky/lib/src/animation/timeline.dart
index 33073493f6aab04f7cb5693779ec6c5ee346394b..294c918930d656f849623a07df851bf73fee18ff 100644
--- a/sky/packages/sky/lib/animation/timeline.dart
+++ b/sky/packages/sky/lib/src/animation/timeline.dart
@@ -5,7 +5,8 @@
 import 'dart:async';
 
 import 'package:newton/newton.dart';
-import 'package:sky/animation/animated_simulation.dart';
+
+import 'package:sky/src/animation/animated_simulation.dart';
 
 // Simple simulation that linearly varies from |begin| to |end| over |duration|.
 class TweenSimulation extends Simulation {
diff --git a/sky/packages/sky/lib/src/rendering/README.md b/sky/packages/sky/lib/src/rendering/README.md
index 91ba8a2ab9b4e4c42cec1507e20a84f5e6a6830a..ff864f2d00b91052235e884e02b9260a45853372 100644
--- a/sky/packages/sky/lib/src/rendering/README.md
+++ b/sky/packages/sky/lib/src/rendering/README.md
@@ -372,8 +372,8 @@ This can be quite useful in figuring out exactly what is going on when
 working with the render tree.
 
 ```dart
-import 'package:sky/src/rendering/sky_binding.dart';
-import 'package:sky/base/scheduler.dart' as scheduler;
+import 'package:sky/animation.dart';
+import 'package:sky/rendering.dart';
 
 scheduler.addPersistentFrameCallback((_) {
   SkyBinding.instance.debugDumpRenderTree();
@@ -384,6 +384,6 @@ scheduler.addPersistentFrameCallback((_) {
 Dependencies
 ------------
 
- * [`package:sky/base`](../base)
- * [`package:sky/mojo`](../mojo)
- * [`package:sky/animation`](../mojo)
+ * [`package:sky/base`](../../base)
+ * [`package:sky/mojo`](../../mojo)
+ * [`package:sky/animation.dart`](../../animation.dart)
diff --git a/sky/packages/sky/lib/src/rendering/object.dart b/sky/packages/sky/lib/src/rendering/object.dart
index 0977c1f3ec5fad1bd792aab38ed778799002e04d..886769038d466f295def2760acaa642e181595e6 100644
--- a/sky/packages/sky/lib/src/rendering/object.dart
+++ b/sky/packages/sky/lib/src/rendering/object.dart
@@ -6,10 +6,10 @@ import 'dart:math' as math;
 import 'dart:sky' as sky;
 import 'dart:sky' show Point, Offset, Size, Rect, Color, Paint, Path;
 
+import 'package:sky/animation.dart';
 import 'package:sky/base/debug.dart';
 import 'package:sky/base/hit_test.dart';
 import 'package:sky/base/node.dart';
-import 'package:sky/base/scheduler.dart' as scheduler;
 import 'package:sky/src/rendering/layer.dart';
 import 'package:vector_math/vector_math.dart';
 
diff --git a/sky/packages/sky/lib/src/rendering/sky_binding.dart b/sky/packages/sky/lib/src/rendering/sky_binding.dart
index bb714d584fd30dfc4124ff27ef4f00d9c8433584..d5ce39530a9fd5ecf480bfd38d10accfa99a8178 100644
--- a/sky/packages/sky/lib/src/rendering/sky_binding.dart
+++ b/sky/packages/sky/lib/src/rendering/sky_binding.dart
@@ -4,9 +4,9 @@
 
 import 'dart:sky' as sky;
 
-import 'package:sky/base/pointer_router.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/base/hit_test.dart';
-import 'package:sky/base/scheduler.dart' as scheduler;
+import 'package:sky/base/pointer_router.dart';
 import 'package:sky/gestures/arena.dart';
 import 'package:sky/src/rendering/box.dart';
 import 'package:sky/src/rendering/object.dart';
@@ -45,7 +45,6 @@ class SkyBinding extends HitTestTarget {
     sky.view.setEventCallback(_handleEvent);
 
     sky.view.setMetricsChangedCallback(_handleMetricsChanged);
-    scheduler.init();
     if (renderViewOverride == null) {
       _renderView = new RenderView(child: root);
       _renderView.attach();
diff --git a/sky/packages/sky/lib/src/rendering/toggleable.dart b/sky/packages/sky/lib/src/rendering/toggleable.dart
index c42d1d8201225c08718ca1cb234f7b00618de402..71673f933d46d3f0fdc3828a613ee2c136b0674c 100644
--- a/sky/packages/sky/lib/src/rendering/toggleable.dart
+++ b/sky/packages/sky/lib/src/rendering/toggleable.dart
@@ -4,9 +4,7 @@
 
 import 'dart:sky' as sky;
 
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/animation_performance.dart';
-import 'package:sky/animation/curves.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/src/rendering/box.dart';
 import 'package:sky/src/rendering/object.dart';
 import 'package:sky/src/rendering/proxy_box.dart';
diff --git a/sky/packages/sky/lib/src/rendering/view.dart b/sky/packages/sky/lib/src/rendering/view.dart
index 0292be3ef4ff2042f8e27cf2a98252f7cadef4ae..943f0957f4bd7581936949ef7075dbe2b8094e37 100644
--- a/sky/packages/sky/lib/src/rendering/view.dart
+++ b/sky/packages/sky/lib/src/rendering/view.dart
@@ -4,7 +4,7 @@
 
 import 'dart:sky' as sky;
 
-import 'package:sky/base/scheduler.dart' as scheduler;
+import 'package:sky/animation.dart';
 import 'package:sky/src/rendering/layer.dart';
 import 'package:sky/src/rendering/object.dart';
 import 'package:sky/src/rendering/box.dart';
diff --git a/sky/packages/sky/lib/src/widgets/README.md b/sky/packages/sky/lib/src/widgets/README.md
index 3deaa763df256753c53a847de829ce45a3bfaf10..0fcb964681f772a4c436651cbb778c8a5d79ed3c 100644
--- a/sky/packages/sky/lib/src/widgets/README.md
+++ b/sky/packages/sky/lib/src/widgets/README.md
@@ -500,8 +500,8 @@ Dependencies
 ------------
 
  * `package:vector_math`
- * [`package:sky/animation`](../animation)
- * [`package:sky/base`](../base)
- * [`package:sky/painting`](../painting)
- * [`package:sky/rendering`](../rendering)
- * [`package:sky/theme`](../theme)
+ * [`package:sky/animation.dart`](../../animation.dart)
+ * [`package:sky/base`](../../base)
+ * [`package:sky/painting`](../../painting)
+ * [`package:sky/rendering.dart`](../../rendering.dart)
+ * [`package:sky/theme`](../../theme)
diff --git a/sky/packages/sky/lib/src/widgets/animated_component.dart b/sky/packages/sky/lib/src/widgets/animated_component.dart
index 2088a4d6a1f9aafb998b1bc73986bf97d37f99b0..f23d884fd33149d4946e3628ee8f113936769ba0 100644
--- a/sky/packages/sky/lib/src/widgets/animated_component.dart
+++ b/sky/packages/sky/lib/src/widgets/animated_component.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:sky/animation/animation_performance.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/src/widgets/framework.dart';
 
 abstract class AnimatedComponent extends StatefulComponent {
diff --git a/sky/packages/sky/lib/src/widgets/animated_container.dart b/sky/packages/sky/lib/src/widgets/animated_container.dart
index a2db6bb20a5c8daa115564e84b31044983b88d24..744f1b65273634b7ee6a8c669416d15e640afb98 100644
--- a/sky/packages/sky/lib/src/widgets/animated_container.dart
+++ b/sky/packages/sky/lib/src/widgets/animated_container.dart
@@ -5,9 +5,7 @@
 import 'dart:sky' as sky;
 
 import 'package:vector_math/vector_math.dart';
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/animation_performance.dart';
-import 'package:sky/animation/curves.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/painting/box_painter.dart';
 import 'package:sky/src/widgets/animated_component.dart';
 import 'package:sky/src/widgets/basic.dart';
diff --git a/sky/packages/sky/lib/src/widgets/dialog.dart b/sky/packages/sky/lib/src/widgets/dialog.dart
index 2db1f1cebc1e570fc8c576191a8be6ab69e7376d..713b63577c3c6f7bc26e7897ba1999df6ef1423f 100644
--- a/sky/packages/sky/lib/src/widgets/dialog.dart
+++ b/sky/packages/sky/lib/src/widgets/dialog.dart
@@ -4,8 +4,7 @@
 
 import 'dart:async';
 
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/curves.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/theme/colors.dart' as colors;
 import 'package:sky/src/widgets/basic.dart';
 import 'package:sky/src/widgets/default_text_style.dart';
diff --git a/sky/packages/sky/lib/src/widgets/dismissable.dart b/sky/packages/sky/lib/src/widgets/dismissable.dart
index a84827572d7dac39f10d15c61e00333cff1e464e..7425cdb0a9a695cfd28fa042a28d9da28505e2cf 100644
--- a/sky/packages/sky/lib/src/widgets/dismissable.dart
+++ b/sky/packages/sky/lib/src/widgets/dismissable.dart
@@ -4,9 +4,7 @@
 
 import 'dart:sky' as sky;
 
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/animation_performance.dart';
-import 'package:sky/animation/curves.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/src/widgets/basic.dart';
 import 'package:sky/src/widgets/transitions.dart';
 import 'package:sky/src/widgets/framework.dart';
diff --git a/sky/packages/sky/lib/src/widgets/drawer.dart b/sky/packages/sky/lib/src/widgets/drawer.dart
index feb2a029660598f8184384256e4eb7b39700a3eb..d6f3ce6ea2ef9c503f7503a72b537a14a5bc653b 100644
--- a/sky/packages/sky/lib/src/widgets/drawer.dart
+++ b/sky/packages/sky/lib/src/widgets/drawer.dart
@@ -5,9 +5,7 @@
 import 'dart:async';
 import 'dart:sky' as sky;
 
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/animation_performance.dart';
-import 'package:sky/animation/forces.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/theme/colors.dart' as colors;
 import 'package:sky/theme/shadows.dart';
 import 'package:sky/src/widgets/animated_container.dart';
@@ -19,8 +17,6 @@ import 'package:sky/src/widgets/scrollable.dart';
 import 'package:sky/src/widgets/theme.dart';
 import 'package:sky/src/widgets/transitions.dart';
 
-export 'package:sky/animation/animation_performance.dart' show AnimationStatus;
-
 // TODO(eseidel): Draw width should vary based on device size:
 // http://www.google.com/design/spec/layout/structure.html#structure-side-nav
 
diff --git a/sky/packages/sky/lib/src/widgets/framework.dart b/sky/packages/sky/lib/src/widgets/framework.dart
index 25138bfe588e5c24e821a7d8acd6e7b25608126b..3f982b72ed4e6cbe3c5b9039c0df74419f91e796 100644
--- a/sky/packages/sky/lib/src/widgets/framework.dart
+++ b/sky/packages/sky/lib/src/widgets/framework.dart
@@ -6,8 +6,8 @@ import 'dart:async';
 import 'dart:collection';
 import 'dart:sky' as sky;
 
+import 'package:sky/animation.dart';
 import 'package:sky/base/hit_test.dart';
-import 'package:sky/base/scheduler.dart' as scheduler;
 import 'package:sky/mojo/activity.dart';
 import 'package:sky/src/rendering/box.dart';
 import 'package:sky/src/rendering/object.dart';
diff --git a/sky/packages/sky/lib/src/widgets/ink_well.dart b/sky/packages/sky/lib/src/widgets/ink_well.dart
index 584491212c94a2be2567d3801282a2683e48be6e..503956610d5f2d6951e2ce6415330e55ba68bb23 100644
--- a/sky/packages/sky/lib/src/widgets/ink_well.dart
+++ b/sky/packages/sky/lib/src/widgets/ink_well.dart
@@ -5,12 +5,8 @@
 import 'dart:math' as math;
 import 'dart:sky' as sky;
 
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/animation_performance.dart';
-import 'package:sky/animation/curves.dart';
-import 'package:sky/src/rendering/box.dart';
-import 'package:sky/src/rendering/object.dart';
-import 'package:sky/src/rendering/proxy_box.dart';
+import 'package:sky/animation.dart';
+import 'package:sky/rendering.dart';
 import 'package:sky/src/widgets/basic.dart';
 import 'package:sky/src/widgets/framework.dart';
 
diff --git a/sky/packages/sky/lib/src/widgets/mimic_overlay.dart b/sky/packages/sky/lib/src/widgets/mimic_overlay.dart
index f4958d6ab012bfb385c767a2a0261321f9352aa3..9c7c742db31dd4773137b026fff30f06c8bb74c6 100644
--- a/sky/packages/sky/lib/src/widgets/mimic_overlay.dart
+++ b/sky/packages/sky/lib/src/widgets/mimic_overlay.dart
@@ -2,9 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/animation_performance.dart';
-import 'package:sky/animation/curves.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/src/widgets/animated_component.dart';
 import 'package:sky/src/widgets/basic.dart';
 import 'package:sky/src/widgets/framework.dart';
diff --git a/sky/packages/sky/lib/src/widgets/navigator.dart b/sky/packages/sky/lib/src/widgets/navigator.dart
index 8fa3a1107fff081cbaf7c7a50b1d29679ec35513..07e97a7732cda880c00c95640953d6985bfd42b2 100644
--- a/sky/packages/sky/lib/src/widgets/navigator.dart
+++ b/sky/packages/sky/lib/src/widgets/navigator.dart
@@ -2,9 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/animation_performance.dart';
-import 'package:sky/animation/curves.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/src/widgets/basic.dart';
 import 'package:sky/src/widgets/focus.dart';
 import 'package:sky/src/widgets/framework.dart';
diff --git a/sky/packages/sky/lib/src/widgets/popup_menu.dart b/sky/packages/sky/lib/src/widgets/popup_menu.dart
index f08d7b7d97ca23038a156653925a7cfda1483e17..49185d08cd548ba58c0c2113944faa643211a6a1 100644
--- a/sky/packages/sky/lib/src/widgets/popup_menu.dart
+++ b/sky/packages/sky/lib/src/widgets/popup_menu.dart
@@ -4,8 +4,7 @@
 
 import 'dart:sky' as sky;
 
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/animation_performance.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/painting/box_painter.dart';
 import 'package:sky/theme/colors.dart';
 import 'package:sky/theme/shadows.dart';
@@ -16,8 +15,6 @@ import 'package:sky/src/widgets/popup_menu_item.dart';
 import 'package:sky/src/widgets/scrollable.dart';
 import 'package:sky/src/widgets/transitions.dart';
 
-export 'package:sky/animation/animation_performance.dart' show AnimationStatus;
-
 const Duration _kMenuDuration = const Duration(milliseconds: 300);
 double _kMenuCloseIntervalEnd = 2.0 / 3.0;
 const double _kMenuWidthStep = 56.0;
diff --git a/sky/packages/sky/lib/src/widgets/progress_indicator.dart b/sky/packages/sky/lib/src/widgets/progress_indicator.dart
index 3688e43d4002409c5969c5580629df39a2ec3363..6a7b683411f4a5d8acae41ca22c6417eb66a5f3d 100644
--- a/sky/packages/sky/lib/src/widgets/progress_indicator.dart
+++ b/sky/packages/sky/lib/src/widgets/progress_indicator.dart
@@ -5,9 +5,7 @@
 import 'dart:math' as math;
 import 'dart:sky' as sky;
 
-import 'package:sky/animation/animation_performance.dart';
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/curves.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/src/widgets/basic.dart';
 import 'package:sky/src/widgets/theme.dart';
 import 'package:sky/src/widgets/framework.dart';
diff --git a/sky/packages/sky/lib/src/widgets/scrollable.dart b/sky/packages/sky/lib/src/widgets/scrollable.dart
index 6789534cd09ec551146d94da68613f2cc3cec21f..b803fa55eabe9d500b6810100affab5506ddad9c 100644
--- a/sky/packages/sky/lib/src/widgets/scrollable.dart
+++ b/sky/packages/sky/lib/src/widgets/scrollable.dart
@@ -7,11 +7,7 @@ import 'dart:math' as math;
 import 'dart:sky' as sky;
 
 import 'package:newton/newton.dart';
-import 'package:sky/animation/animated_simulation.dart';
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/animation_performance.dart';
-import 'package:sky/animation/curves.dart';
-import 'package:sky/animation/scroll_behavior.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/gestures/constants.dart';
 import 'package:sky/src/rendering/box.dart';
 import 'package:sky/src/rendering/viewport.dart';
diff --git a/sky/packages/sky/lib/src/widgets/snack_bar.dart b/sky/packages/sky/lib/src/widgets/snack_bar.dart
index 2e5a521a94e78664ed7bf7536becc4adf0ca9c3e..eae0ae8920fbd96fa09c9ae245f7fdbda00b594a 100644
--- a/sky/packages/sky/lib/src/widgets/snack_bar.dart
+++ b/sky/packages/sky/lib/src/widgets/snack_bar.dart
@@ -3,9 +3,7 @@
 // found in the LICENSE file.
 
 
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/animation_performance.dart';
-import 'package:sky/animation/curves.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/painting/text_style.dart';
 import 'package:sky/theme/typography.dart' as typography;
 import 'package:sky/src/widgets/basic.dart';
@@ -16,8 +14,6 @@ import 'package:sky/src/widgets/material.dart';
 import 'package:sky/src/widgets/theme.dart';
 import 'package:sky/src/widgets/transitions.dart';
 
-export 'package:sky/animation/animation_performance.dart' show AnimationStatus;
-
 typedef void SnackBarDismissedCallback();
 
 const Duration _kSlideInDuration = const Duration(milliseconds: 200);
diff --git a/sky/packages/sky/lib/src/widgets/tabs.dart b/sky/packages/sky/lib/src/widgets/tabs.dart
index 804efe3ad75b46247bf18264db0fab47245796b3..3a3d8fce7d9cd56bceda65a0f66125e0757dac70 100644
--- a/sky/packages/sky/lib/src/widgets/tabs.dart
+++ b/sky/packages/sky/lib/src/widgets/tabs.dart
@@ -6,14 +6,9 @@ import 'dart:math' as math;
 import 'dart:sky' as sky;
 
 import 'package:newton/newton.dart';
-import 'package:sky/animation/animation_performance.dart';
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/curves.dart';
-import 'package:sky/animation/scroll_behavior.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/painting/text_style.dart';
-import 'package:sky/src/rendering/box.dart';
-import 'package:sky/src/rendering/object.dart';
-import 'package:sky/src/rendering/viewport.dart';
+import 'package:sky/rendering.dart';
 import 'package:sky/theme/colors.dart' as colors;
 import 'package:sky/theme/typography.dart' as typography;
 import 'package:sky/src/widgets/basic.dart';
diff --git a/sky/packages/sky/lib/src/widgets/transitions.dart b/sky/packages/sky/lib/src/widgets/transitions.dart
index d94a6b721fa6cf36b9a3bb3cfd8bfd2dd80b44df..35e431ef61faf78f8ec509ed7be8322ff1293e6e 100644
--- a/sky/packages/sky/lib/src/widgets/transitions.dart
+++ b/sky/packages/sky/lib/src/widgets/transitions.dart
@@ -2,14 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:sky/animation/animated_value.dart';
-import 'package:sky/animation/animation_performance.dart';
+import 'package:sky/animation.dart';
 import 'package:sky/src/widgets/animated_component.dart';
 import 'package:sky/src/widgets/basic.dart';
 import 'package:sky/src/widgets/framework.dart';
 import 'package:vector_math/vector_math.dart';
 
-export 'package:sky/animation/direction.dart' show Direction;
+export 'package:sky/animation.dart' show Direction;
 
 // A helper class to anchor widgets to one another. Pass an instance of this to
 // a Transition, then use the build() method to create a child with the same
diff --git a/sky/unit/test/base/scheduler_test.dart b/sky/unit/test/animation/scheduler_test.dart
similarity index 95%
rename from sky/unit/test/base/scheduler_test.dart
rename to sky/unit/test/animation/scheduler_test.dart
index a49379734ce172412495ceddbdb420c6e8d170b2..380de02bb3e751f1b1d2505ecba8b78661c00eb6 100644
--- a/sky/unit/test/base/scheduler_test.dart
+++ b/sky/unit/test/animation/scheduler_test.dart
@@ -1,4 +1,4 @@
-import 'package:sky/base/scheduler.dart' as scheduler;
+import 'package:sky/animation.dart';
 import 'package:test/test.dart';
 
 void main() {
diff --git a/sky/unit/test/widget/widget_tester.dart b/sky/unit/test/widget/widget_tester.dart
index ae1da3f2d46c8036f92bd2ea4979f87518fead76..356f45b307486c4a790fa09bf993a1b47926e349 100644
--- a/sky/unit/test/widget/widget_tester.dart
+++ b/sky/unit/test/widget/widget_tester.dart
@@ -1,8 +1,8 @@
 import 'dart:sky' as sky;
 
+import 'package:sky/animation.dart';
 import 'package:sky/rendering.dart';
 import 'package:sky/widgets.dart';
-import 'package:sky/base/scheduler.dart' as scheduler;
 
 import '../engine/mock_events.dart';
 
diff --git a/skysprites/lib/skysprites.dart b/skysprites/lib/skysprites.dart
index 3bb57b1d2f4b4dc75030e2109b26f663e3e2b9fe..9d300e7f5c7b272b820b804ee979eba11c8208e2 100644
--- a/skysprites/lib/skysprites.dart
+++ b/skysprites/lib/skysprites.dart
@@ -11,8 +11,7 @@ import 'dart:typed_data';
 import 'dart:sky';
 
 import 'package:mojo/core.dart';
-import 'package:sky/animation/curves.dart';
-import 'package:sky/base/scheduler.dart' as scheduler;
+import 'package:sky/animation.dart';
 import 'package:sky/mojo/asset_bundle.dart';
 import 'package:sky/mojo/shell.dart' as shell;
 import 'package:sky/painting/text_painter.dart';