diff --git a/Perspex.Layout/LayoutHelper.cs b/Perspex.Layout/LayoutHelper.cs
index dc365685ae..95e8750cd9 100644
--- a/Perspex.Layout/LayoutHelper.cs
+++ b/Perspex.Layout/LayoutHelper.cs
@@ -1,6 +1,6 @@
 // -----------------------------------------------------------------------
 // <copyright file="LayoutHelper.cs" company="Steven Kirk">
-// Copyright 2014 MIT Licence. See licence.md for more information.
+// Copyright 2015 MIT Licence. See licence.md for more information.
 // </copyright>
 // -----------------------------------------------------------------------
 
@@ -8,8 +8,20 @@ namespace Perspex.Layout
 {
     using System;
 
+    /// <summary>
+    /// Provides helper methods needed for layout.
+    /// </summary>
     public static class LayoutHelper
     {
+        /// <summary>
+        /// Calculates a control's size based on its <see cref="ILayoutable.Width"/>,
+        /// <see cref="ILayoutable.Height"/>, <see cref="ILayoutable.MinWidth"/>,
+        /// <see cref="ILayoutable.MaxWidth"/>, <see cref="ILayoutable.MinHeight"/> and
+        /// <see cref="ILayoutable.MaxHeight"/>.
+        /// </summary>
+        /// <param name="control">The control.</param>
+        /// <param name="constraints">The space available for the control.</param>
+        /// <returns>The control's size.</returns>
         public static Size ApplyLayoutConstraints(ILayoutable control, Size constraints)
         {
             double width = (control.Width > 0) ? control.Width : constraints.Width;
diff --git a/Perspex.Layout/LayoutManager.cs b/Perspex.Layout/LayoutManager.cs
index e2bdaf8fba..e6c6628993 100644
--- a/Perspex.Layout/LayoutManager.cs
+++ b/Perspex.Layout/LayoutManager.cs
@@ -302,18 +302,37 @@ namespace Perspex.Layout
             }
         }
 
+        /// <summary>
+        /// An item to be layed-out.
+        /// </summary>
         private class Item : IComparable<Item>
         {
+            /// <summary>
+            /// Initializes a new instance of the <see cref="Item"/> class.
+            /// </summary>
+            /// <param name="control">The control.</param>
+            /// <param name="distance">The control's distance from the layout root.</param>
             public Item(ILayoutable control, int distance)
             {
                 this.Control = control;
                 this.Distance = distance;
             }
 
-            public ILayoutable Control { get; private set; }
-
-            public int Distance { get; private set; }
-
+            /// <summary>
+            /// Gets the control.
+            /// </summary>
+            public ILayoutable Control { get; }
+
+            /// <summary>
+            /// Gets the control's distance from the layout root.
+            /// </summary>
+            public int Distance { get; }
+
+            /// <summary>
+            /// Compares the distance of two items.
+            /// </summary>
+            /// <param name="other">The other item/</param>
+            /// <returns>The comparison.</returns>
             public int CompareTo(Item other)
             {
                 return this.Distance - other.Distance;
diff --git a/Perspex.SceneGraph/VisualTree/BoundsTracker.cs b/Perspex.SceneGraph/VisualTree/BoundsTracker.cs
index 35dd95b867..be81c4ebe4 100644
--- a/Perspex.SceneGraph/VisualTree/BoundsTracker.cs
+++ b/Perspex.SceneGraph/VisualTree/BoundsTracker.cs
@@ -11,13 +11,30 @@ namespace Perspex.VisualTree
     using System.Linq;
     using System.Reactive.Linq;
 
+    /// <summary>
+    /// Tracks the bounds of a control.
+    /// </summary>
+    /// <remarks>
+    /// This class is used by Adorners to track the control that the adorner is attached to.
+    /// </remarks>
     public class BoundsTracker
     {
+        /// <summary>
+        /// Starts tracking the specified visual.
+        /// </summary>
+        /// <param name="visual">The visual.</param>
+        /// <returns>An observable that returns the tracked bounds.</returns>
         public IObservable<TransformedBounds> Track(Visual visual)
         {
             return this.Track(visual, (Visual)visual.GetVisualRoot());
         }
 
+        /// <summary>
+        /// Starts tracking the specified visual relative to another control.
+        /// </summary>
+        /// <param name="visual">The visual.</param>
+        /// <param name="relativeTo">The control that the tracking should be relative to.</param>
+        /// <returns>An observable that returns the tracked bounds.</returns>
         public IObservable<TransformedBounds> Track(Visual visual, Visual relativeTo)
         {
             var visuals = visual.GetSelfAndVisualAncestors()
@@ -36,6 +53,11 @@ namespace Perspex.VisualTree
             return Observable.Select(bounds, x => new TransformedBounds((Rect)x, (Rect)new Rect(), (Matrix)Matrix.Identity));
         }
 
+        /// <summary>
+        /// Sums a collection of rectangles.
+        /// </summary>
+        /// <param name="rects">The collection of rectangles.</param>
+        /// <returns>The summed rectangle.</returns>
         private static Rect ExtractBounds(IList<Rect> rects)
         {
             var position = rects.Select(x => x.Position).Aggregate((a, b) => a + b);
diff --git a/Perspex.SceneGraph/VisualTree/TransformedBounds.cs b/Perspex.SceneGraph/VisualTree/TransformedBounds.cs
index b241d88a43..a7f9165486 100644
--- a/Perspex.SceneGraph/VisualTree/TransformedBounds.cs
+++ b/Perspex.SceneGraph/VisualTree/TransformedBounds.cs
@@ -6,8 +6,17 @@
 
 namespace Perspex.VisualTree
 {
+    /// <summary>
+    /// Holds information about the bounds of a control, together with a transform and a clip/
+    /// </summary>
     public class TransformedBounds
     {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TransformedBounds"/> class.
+        /// </summary>
+        /// <param name="bounds">The control's bounds.</param>
+        /// <param name="clip">The control's clip rectangle.</param>
+        /// <param name="transform">The control's transform.</param>
         public TransformedBounds(Rect bounds, Rect clip, Matrix transform)
         {
             this.Bounds = bounds;
@@ -15,10 +24,19 @@ namespace Perspex.VisualTree
             this.Transform = transform;
         }
 
+        /// <summary>
+        /// Gets the control's bounds.
+        /// </summary>
         public Rect Bounds { get; }
 
+        /// <summary>
+        /// Gets the control's clip rectangle.
+        /// </summary>
         public Rect Clip { get; }
 
+        /// <summary>
+        /// Gets the control's transform.
+        /// </summary>
         public Matrix Transform { get;  }
     }
 }
diff --git a/Windows/Perspex.Direct2D1/Media/GeometryImpl.cs b/Windows/Perspex.Direct2D1/Media/GeometryImpl.cs
index f93911d553..0cd3952579 100644
--- a/Windows/Perspex.Direct2D1/Media/GeometryImpl.cs
+++ b/Windows/Perspex.Direct2D1/Media/GeometryImpl.cs
@@ -1,6 +1,6 @@
 // -----------------------------------------------------------------------
 // <copyright file="GeometryImpl.cs" company="Steven Kirk">
-// Copyright 2014 MIT Licence. See licence.md for more information.
+// Copyright 2015 MIT Licence. See licence.md for more information.
 // </copyright>
 // -----------------------------------------------------------------------
 
@@ -10,25 +10,40 @@ namespace Perspex.Direct2D1.Media
     using SharpDX.Direct2D1;
     using Splat;
 
+    /// <summary>
+    /// The platform-specific interface for <see cref="Perspex.Media.Geometry"/>.
+    /// </summary>
     public abstract class GeometryImpl : IGeometryImpl
     {
         private TransformedGeometry transformed;
 
+        /// <summary>
+        /// Gets the geometry's bounding rectangle.
+        /// </summary>
         public abstract Rect Bounds
         {
             get;
         }
 
+        /// <summary>
+        /// Gets the geomentry without any transforms applied.
+        /// </summary>
         public abstract Geometry DefiningGeometry
         {
             get;
         }
 
+        /// <summary>
+        /// Gets the Direct2D <see cref="Geometry"/>.
+        /// </summary>
         public Geometry Geometry
         {
             get { return this.transformed ?? this.DefiningGeometry; }
         }
 
+        /// <summary>
+        /// Gets or sets the transform for the geometry.
+        /// </summary>
         public Matrix Transform
         {
             get
@@ -60,6 +75,11 @@ namespace Perspex.Direct2D1.Media
             }
         }
 
+        /// <summary>
+        /// Gets the geometry's bounding rectangle with the specified stroke thickness.
+        /// </summary>
+        /// <param name="strokeThickness">The stroke thickness.</param>
+        /// <returns>The bounding rectangle.</returns>
         public Rect GetRenderBounds(double strokeThickness)
         {
             if (this.transformed != null)
diff --git a/Windows/Perspex.Direct2D1/Media/Imaging/BitmapImpl.cs b/Windows/Perspex.Direct2D1/Media/Imaging/BitmapImpl.cs
index af09444545..40518a553a 100644
--- a/Windows/Perspex.Direct2D1/Media/Imaging/BitmapImpl.cs
+++ b/Windows/Perspex.Direct2D1/Media/Imaging/BitmapImpl.cs
@@ -11,12 +11,20 @@ namespace Perspex.Direct2D1.Media
     using Perspex.Platform;
     using SharpDX.WIC;
 
+    /// <summary>
+    /// A Direct2D implementation of a <see cref="Perspex.Media.Imaging.Bitmap"/>.
+    /// </summary>
     public class BitmapImpl : IBitmapImpl
     {
         private ImagingFactory factory;
 
         private SharpDX.Direct2D1.Bitmap direct2D;
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="BitmapImpl"/> class.
+        /// </summary>
+        /// <param name="factory">The WIC imaging factory to use.</param>
+        /// <param name="fileName">The filename of the bitmap to load.</param>
         public BitmapImpl(ImagingFactory factory, string fileName)
         {
             this.factory = factory;
@@ -27,6 +35,12 @@ namespace Perspex.Direct2D1.Media
             }
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="BitmapImpl"/> class.
+        /// </summary>
+        /// <param name="factory">The WIC imaging factory to use.</param>
+        /// <param name="width">The width of the bitmap.</param>
+        /// <param name="height">The height of the bitmap.</param>
         public BitmapImpl(ImagingFactory factory, int width, int height)
         {
             this.factory = factory;
@@ -38,22 +52,36 @@ namespace Perspex.Direct2D1.Media
                 BitmapCreateCacheOption.CacheOnLoad);
         }
 
-        public int PixelHeight
+        /// <summary>
+        /// Gets the width of the bitmap, in pixels.
+        /// </summary>
+        public int PixelWidth
         {
-            get { return this.WicImpl.Size.Width; }
+            get { return this.WicImpl.Size.Height; }
         }
 
-        public int PixelWidth
+        /// <summary>
+        /// Gets the height of the bitmap, in pixels.
+        /// </summary>
+        public int PixelHeight
         {
-            get { return this.WicImpl.Size.Height; }
+            get { return this.WicImpl.Size.Width; }
         }
 
+        /// <summary>
+        /// Gets the WIC implementation of the bitmap.
+        /// </summary>
         public Bitmap WicImpl
         {
             get;
             private set;
         }
 
+        /// <summary>
+        /// Gets a Direct2D bitmap to use on the specified render target.
+        /// </summary>
+        /// <param name="renderTarget">The render target.</param>
+        /// <returns>The Direct2D bitmap.</returns>
         public SharpDX.Direct2D1.Bitmap GetDirect2DBitmap(SharpDX.Direct2D1.RenderTarget renderTarget)
         {
             if (this.direct2D == null)
@@ -66,6 +94,10 @@ namespace Perspex.Direct2D1.Media
             return this.direct2D;
         }
 
+        /// <summary>
+        /// Saves the bitmap to a file.
+        /// </summary>
+        /// <param name="fileName">The filename.</param>
         public void Save(string fileName)
         {
             if (Path.GetExtension(fileName) != ".png")
diff --git a/Windows/Perspex.Direct2D1/Media/StreamGeometryImpl.cs b/Windows/Perspex.Direct2D1/Media/StreamGeometryImpl.cs
index 9bd9082844..f446934df4 100644
--- a/Windows/Perspex.Direct2D1/Media/StreamGeometryImpl.cs
+++ b/Windows/Perspex.Direct2D1/Media/StreamGeometryImpl.cs
@@ -1,44 +1,58 @@
 // -----------------------------------------------------------------------
 // <copyright file="StreamGeometryImpl.cs" company="Steven Kirk">
-// Copyright 2014 MIT Licence. See licence.md for more information.
+// Copyright 2015 MIT Licence. See licence.md for more information.
 // </copyright>
 // -----------------------------------------------------------------------
 
 namespace Perspex.Direct2D1.Media
 {
-    using System;
     using Perspex.Media;
     using Perspex.Platform;
-    using SharpDX;
     using SharpDX.Direct2D1;
     using Splat;
     using D2DGeometry = SharpDX.Direct2D1.Geometry;
 
+    /// <summary>
+    /// A Direct2D implementation of a <see cref="StreamGeometry"/>.
+    /// </summary>
     public class StreamGeometryImpl : GeometryImpl, IStreamGeometryImpl
     {
         private PathGeometry path;
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="StreamGeometryImpl"/> class.
+        /// </summary>
         public StreamGeometryImpl()
         {
             Factory factory = Locator.Current.GetService<Factory>();
             this.path = new PathGeometry(factory);
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="StreamGeometryImpl"/> class.
+        /// </summary>
+        /// <param name="geometry">An existing Direct2D <see cref="PathGeometry"/>.</param>
         protected StreamGeometryImpl(PathGeometry geometry)
         {
             this.path = geometry;
         }
 
+        /// <inheritdoc/>
         public override Rect Bounds
         {
             get { return this.path.GetBounds().ToPerspex(); }
         }
 
+        /// <inheritdoc/>
         public override D2DGeometry DefiningGeometry
         {
             get { return this.path; }
         }
 
+        /// <summary>
+        /// Clones the geometry.
+        /// </summary>
+        /// <returns>A cloned geometry.</returns>
         public IStreamGeometryImpl Clone()
         {
             Factory factory = Locator.Current.GetService<Factory>();
@@ -49,6 +63,12 @@ namespace Perspex.Direct2D1.Media
             return new StreamGeometryImpl(result);
         }
 
+        /// <summary>
+        /// Opens the geometry to start defining it.
+        /// </summary>
+        /// <returns>
+        /// A <see cref="StreamGeometryContext"/> which can be used to define the geometry.
+        /// </returns>
         public IStreamGeometryContextImpl Open()
         {
             return new StreamGeometryContextImpl(this.path.Open());