diff --git a/Perspex.Controls/Platform/IWindowImpl.cs b/Perspex.Controls/Platform/IWindowImpl.cs
index 83586d3e9f..f937017901 100644
--- a/Perspex.Controls/Platform/IWindowImpl.cs
+++ b/Perspex.Controls/Platform/IWindowImpl.cs
@@ -1,22 +1,40 @@
 // -----------------------------------------------------------------------
 // <copyright file="IWindowImpl.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.Platform
 {
     using System;
-    using System.Threading.Tasks;
 
+    /// <summary>
+    /// Defines a platform-specific window implementation.
+    /// </summary>
     public interface IWindowImpl : ITopLevelImpl
     {
+        /// <summary>
+        /// Sets the title of the window.
+        /// </summary>
+        /// <param name="title">The title.</param>
         void SetTitle(string title);
 
+        /// <summary>
+        /// Shows the window.
+        /// </summary>
         void Show();
 
+        /// <summary>
+        /// Shows the window as a dialog.
+        /// </summary>
+        /// <returns>
+        /// An <see cref="IDisposable"/> that should be used to close the window.
+        /// </returns>
         IDisposable ShowDialog();
 
+        /// <summary>
+        /// Hides the window.
+        /// </summary>
         void Hide();
     }
 }
diff --git a/Perspex.SceneGraph/Media/EllipseGeometry.cs b/Perspex.SceneGraph/Media/EllipseGeometry.cs
index 625ad176dd..6c31dda4a7 100644
--- a/Perspex.SceneGraph/Media/EllipseGeometry.cs
+++ b/Perspex.SceneGraph/Media/EllipseGeometry.cs
@@ -1,6 +1,6 @@
 // -----------------------------------------------------------------------
 // <copyright file="EllipseGeometry.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>
 // -----------------------------------------------------------------------
 
@@ -10,8 +10,15 @@ namespace Perspex.Media
     using Perspex.Platform;
     using Splat;
 
+    /// <summary>
+    /// Represents the geometry of an ellipse or circle.
+    /// </summary>
     public class EllipseGeometry : Geometry
     {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="EllipseGeometry"/> class.
+        /// </summary>
+        /// <param name="rect">The rectangle that the ellipse should fill.</param>
         public EllipseGeometry(Rect rect)
         {
             IPlatformRenderInterface factory = Locator.Current.GetService<IPlatformRenderInterface>();
@@ -46,11 +53,13 @@ namespace Perspex.Media
             this.PlatformImpl = impl;
         }
 
+        /// <inheritdoc/>
         public override Rect Bounds
         {
             get { return this.PlatformImpl.Bounds; }
         }
 
+        /// <inheritdoc/>
         public override Geometry Clone()
         {
             return new EllipseGeometry(this.Bounds);
diff --git a/Perspex.SceneGraph/Media/Geometry.cs b/Perspex.SceneGraph/Media/Geometry.cs
index 0d30a8ca3b..77dede97ae 100644
--- a/Perspex.SceneGraph/Media/Geometry.cs
+++ b/Perspex.SceneGraph/Media/Geometry.cs
@@ -9,11 +9,20 @@ namespace Perspex.Media
     using System;
     using Perspex.Platform;
 
+    /// <summary>
+    /// Defines a geometric shape.
+    /// </summary>
     public abstract class Geometry : PerspexObject
     {
+        /// <summary>
+        /// Defines the <see cref="Transform"/> property.
+        /// </summary>
         public static readonly PerspexProperty<Transform> TransformProperty =
             PerspexProperty.Register<Geometry, Transform>("Transform");
 
+        /// <summary>
+        /// Initializes static members of the <see cref="Geometry"/> class.
+        /// </summary>
         static Geometry()
         {
             TransformProperty.Changed.Subscribe(x =>
@@ -22,25 +31,43 @@ namespace Perspex.Media
             });
         }
 
+        /// <summary>
+        /// Gets the geometry's bounding rectangle.
+        /// </summary>
         public abstract Rect Bounds
         {
             get;
         }
 
+        /// <summary>
+        /// Gets the platform-specific implementation of the geometry.
+        /// </summary>
         public IGeometryImpl PlatformImpl
         {
             get;
             protected set;
         }
 
+        /// <summary>
+        /// Gets or sets a transform to apply to the geometry.
+        /// </summary>
         public Transform Transform
         {
             get { return this.GetValue(TransformProperty); }
             set { this.SetValue(TransformProperty, value); }
         }
 
+        /// <summary>
+        /// Clones the geometry.
+        /// </summary>
+        /// <returns>A cloned geometry.</returns>
         public abstract Geometry Clone();
 
+        /// <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)
         {
             return this.PlatformImpl.GetRenderBounds(strokeThickness);
diff --git a/Perspex.SceneGraph/Media/RectangleGeometry.cs b/Perspex.SceneGraph/Media/RectangleGeometry.cs
index 6d89919e26..a2aa83cd76 100644
--- a/Perspex.SceneGraph/Media/RectangleGeometry.cs
+++ b/Perspex.SceneGraph/Media/RectangleGeometry.cs
@@ -1,17 +1,23 @@
 // -----------------------------------------------------------------------
 // <copyright file="RectangleGeometry.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.Media
 {
-    using System;
     using Perspex.Platform;
     using Splat;
 
+    /// <summary>
+    /// Represents the geometry of a rectangle.
+    /// </summary>
     public class RectangleGeometry : Geometry
     {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RectangleGeometry"/> class.
+        /// </summary>
+        /// <param name="rect">The rectangle bounds.</param>
         public RectangleGeometry(Rect rect)
         {
             IPlatformRenderInterface factory = Locator.Current.GetService<IPlatformRenderInterface>();
@@ -29,11 +35,13 @@ namespace Perspex.Media
             this.PlatformImpl = impl;
         }
 
+        /// <inheritdoc/>
         public override Rect Bounds
         {
             get { return this.PlatformImpl.Bounds; }
         }
 
+        /// <inheritdoc/>
         public override Geometry Clone()
         {
             return new RectangleGeometry(this.Bounds);
diff --git a/Perspex.SceneGraph/Media/StreamGeometry.cs b/Perspex.SceneGraph/Media/StreamGeometry.cs
index f2a013d1ad..8e5eb6425a 100644
--- a/Perspex.SceneGraph/Media/StreamGeometry.cs
+++ b/Perspex.SceneGraph/Media/StreamGeometry.cs
@@ -1,33 +1,48 @@
 // -----------------------------------------------------------------------
 // <copyright file="StreamGeometry.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.Media
 {
-    using System;
     using Perspex.Platform;
     using Splat;
 
+    /// <summary>
+    /// Represents the geometry of an arbitrarily complex shape.
+    /// </summary>
     public class StreamGeometry : Geometry
     {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="StreamGeometry"/> class.
+        /// </summary>
         public StreamGeometry()
         {
             IPlatformRenderInterface factory = Locator.Current.GetService<IPlatformRenderInterface>();
             this.PlatformImpl = factory.CreateStreamGeometry();
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="StreamGeometry"/> class.
+        /// </summary>
+        /// <param name="impl">The platform-specific implementation.</param>
         private StreamGeometry(IGeometryImpl impl)
         {
             this.PlatformImpl = impl;
         }
 
+        /// <inheritdoc/>
         public override Rect Bounds
         {
             get { return this.PlatformImpl.Bounds; }
         }
 
+        /// <summary>
+        /// Creates a <see cref="StreamGeometry"/> from a string.
+        /// </summary>
+        /// <param name="s">The string.</param>
+        /// <returns>A <see cref="StreamGeometry"/>.</returns>
         public static StreamGeometry Parse(string s)
         {
             StreamGeometry result = new StreamGeometry();
@@ -40,11 +55,18 @@ namespace Perspex.Media
             }
         }
 
+        /// <inheritdoc/>
         public override Geometry Clone()
         {
             return new StreamGeometry(((IStreamGeometryImpl)this.PlatformImpl).Clone());
         }
 
+        /// <summary>
+        /// Opens the geometry to start defining it.
+        /// </summary>
+        /// <returns>
+        /// A <see cref="StreamGeometryContext"/> which can be used to define the geometry.
+        /// </returns>
         public StreamGeometryContext Open()
         {
             return new StreamGeometryContext(((IStreamGeometryImpl)this.PlatformImpl).Open());
diff --git a/Perspex.SceneGraph/Media/StreamGeometryContext.cs b/Perspex.SceneGraph/Media/StreamGeometryContext.cs
index 62d24b3d7e..377c89a735 100644
--- a/Perspex.SceneGraph/Media/StreamGeometryContext.cs
+++ b/Perspex.SceneGraph/Media/StreamGeometryContext.cs
@@ -1,6 +1,6 @@
 // -----------------------------------------------------------------------
 // <copyright file="StreamGeometryContext.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>
 // -----------------------------------------------------------------------
 
@@ -9,40 +9,85 @@ namespace Perspex.Media
     using System;
     using Perspex.Platform;
 
+    /// <summary>
+    /// Describes a geometry using drawing commands.
+    /// </summary>
+    /// <remarks>
+    /// This class is used to define the geometry of a <see cref="StreamGeometry"/>. An instance
+    /// of <see cref="StreamGeometryContext"/> is obtained by calling
+    /// <see cref="StreamGeometry.Open"/>.
+    /// </remarks>
+    /// TODO: This class is just a wrapper around IStreamGeometryContextImpl: is it needed?
     public class StreamGeometryContext : IDisposable
     {
         private IStreamGeometryContextImpl impl;
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="StreamGeometryContext"/> class.
+        /// </summary>
+        /// <param name="impl">The platform-specific implementation.</param>
         public StreamGeometryContext(IStreamGeometryContextImpl impl)
         {
             this.impl = impl;
         }
 
+        /// <summary>
+        /// Draws an arc to the specified point.
+        /// </summary>
+        /// <param name="point">The destination point.</param>
+        /// <param name="size">The radii of an oval whose perimeter is used to draw the angle.</param>
+        /// <param name="rotationAngle">The rotation angle of the oval that specifies the curve.</param>
+        /// <param name="isLargeArc">true to draw the arc greater than 180 degrees; otherwise, false.</param>
+        /// <param name="sweepDirection">
+        /// A value that indicates whether the arc is drawn in the Clockwise or Counterclockwise direction.
+        /// </param>
         public void ArcTo(Point point, Size size, double rotationAngle, bool isLargeArc, SweepDirection sweepDirection)
         {
             this.impl.ArcTo(point, size, rotationAngle, isLargeArc, sweepDirection);
         }
 
+        /// <summary>
+        /// Begins a new figure.
+        /// </summary>
+        /// <param name="startPoint">The starting point for the figure.</param>
+        /// <param name="isFilled">Whether the figure is filled.</param>
         public void BeginFigure(Point startPoint, bool isFilled)
         {
             this.impl.BeginFigure(startPoint, isFilled);
         }
 
+        /// <summary>
+        /// Draws a Bezier curve to the specified point.
+        /// </summary>
+        /// <param name="point1">The first control point used to specify the shape of the curve.</param>
+        /// <param name="point2">The second control point used to specify the shape of the curve.</param>
+        /// <param name="point3">The destination point for the end of the curve.</param>
         public void BezierTo(Point point1, Point point2, Point point3)
         {
             this.impl.BezierTo(point1, point2, point3);
         }
 
+        /// <summary>
+        /// Draws a line to the specified point.
+        /// </summary>
+        /// <param name="point">The destination point.</param>
         public void LineTo(Point point)
         {
             this.impl.LineTo(point);
         }
 
+        /// <summary>
+        /// Ends the figure started by <see cref="BeginFigure(Point, bool)"/>.
+        /// </summary>
+        /// <param name="isClosed">Whether the figure is closed.</param>
         public void EndFigure(bool isClosed)
         {
             this.impl.EndFigure(isClosed);
         }
 
+        /// <summary>
+        /// Finishes the drawing session.
+        /// </summary>
         public void Dispose()
         {
             this.impl.Dispose();
diff --git a/Perspex.SceneGraph/Platform/IStreamGeometryContextImpl.cs b/Perspex.SceneGraph/Platform/IStreamGeometryContextImpl.cs
index aacd8801a8..515e296637 100644
--- a/Perspex.SceneGraph/Platform/IStreamGeometryContextImpl.cs
+++ b/Perspex.SceneGraph/Platform/IStreamGeometryContextImpl.cs
@@ -1,6 +1,6 @@
 // -----------------------------------------------------------------------
 // <copyright file="IStreamGeometryContextImpl.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>
 // -----------------------------------------------------------------------
 
@@ -9,16 +9,48 @@ namespace Perspex.Platform
     using System;
     using Perspex.Media;
 
+    /// <summary>
+    /// Describes a geometry using drawing commands.
+    /// </summary>
     public interface IStreamGeometryContextImpl : IDisposable
     {
+        /// <summary>
+        /// Draws an arc to the specified point.
+        /// </summary>
+        /// <param name="point">The destination point.</param>
+        /// <param name="size">The radii of an oval whose perimeter is used to draw the angle.</param>
+        /// <param name="rotationAngle">The rotation angle of the oval that specifies the curve.</param>
+        /// <param name="isLargeArc">true to draw the arc greater than 180 degrees; otherwise, false.</param>
+        /// <param name="sweepDirection">
+        /// A value that indicates whether the arc is drawn in the Clockwise or Counterclockwise direction.
+        /// </param>
         void ArcTo(Point point, Size size, double rotationAngle, bool isLargeArc, SweepDirection sweepDirection);
 
+        /// <summary>
+        /// Begins a new figure.
+        /// </summary>
+        /// <param name="startPoint">The starting point for the figure.</param>
+        /// <param name="isFilled">Whether the figure is filled.</param>
         void BeginFigure(Point startPoint, bool isFilled);
 
+        /// <summary>
+        /// Draws a Bezier curve to the specified point.
+        /// </summary>
+        /// <param name="point1">The first control point used to specify the shape of the curve.</param>
+        /// <param name="point2">The second control point used to specify the shape of the curve.</param>
+        /// <param name="point3">The destination point for the end of the curve.</param>
         void BezierTo(Point point1, Point point2, Point point3);
 
+        /// <summary>
+        /// Draws a line to the specified point.
+        /// </summary>
+        /// <param name="point">The destination point.</param>
         void LineTo(Point point);
 
+        /// <summary>
+        /// Ends the figure started by <see cref="BeginFigure(Point, bool)"/>.
+        /// </summary>
+        /// <param name="isClosed">Whether the figure is closed.</param>
         void EndFigure(bool isClosed);
     }
 }