diff --git a/Perspex.Controls/ToolTip.cs b/Perspex.Controls/ToolTip.cs
index c8eb095d44..91fd3c6d82 100644
--- a/Perspex.Controls/ToolTip.cs
+++ b/Perspex.Controls/ToolTip.cs
@@ -6,41 +6,81 @@
 
 namespace Perspex.Controls
 {
+    using Perspex.Input;
+    using Perspex.Threading;
     using System;
-    using System.Reactive;
     using System.Reactive.Linq;
     using System.Reactive.Subjects;
-    using Perspex.Input;
-    using Perspex.Threading;
-    using Perspex.VisualTree;
 
+    /// <summary>
+    /// A tooltip control.
+    /// </summary>
+    /// <remarks>
+    /// You will probably not want to create a <see cref="ToolTip"/> control directly: if added to 
+    /// the tree it will act as a simple <see cref="ContentControl"/> styled to look like a tooltip.
+    /// To add a tooltip to a control, use the <see cref="TipProperty"/> attached property, 
+    /// assigning the content that you want displayed.
+    /// </remarks>
     public class ToolTip : ContentControl
     {
+        /// <summary>
+        /// Defines the ToolTip.Tip attached property.
+        /// </summary>
         public static readonly PerspexProperty<object> TipProperty =
             PerspexProperty.RegisterAttached<ToolTip, Control, object>("Tip");
 
+        /// <summary>
+        /// The popup window used to display the active tooltip.
+        /// </summary>
         private static PopupRoot popup;
 
+        /// <summary>
+        /// The control that the currently visible tooltip is attached to.
+        /// </summary>
         private static Control current;
 
+        /// <summary>
+        /// Observable fired when a tooltip should be displayed for a control. The output from this
+        /// observable is throttled and calls <see cref="ShowToolTip(Control)"/> when the time 
+        /// period expires.
+        /// </summary>
         private static Subject<Control> show = new Subject<Control>();
 
+        /// <summary>
+        /// Statically constructs the tooltip class.
+        /// </summary>
         static ToolTip()
         {
             TipProperty.Changed.Subscribe(TipChanged);
             show.Throttle(TimeSpan.FromSeconds(0.5), PerspexScheduler.Instance).Subscribe(ShowToolTip);
         }
 
+        /// <summary>
+        /// Gets the value of the ToolTip.Tip attached property.
+        /// </summary>
+        /// <param name="element">The control to get the property from.</param>
+        /// <returns>
+        /// The content to be displayed in the control's tooltip.
+        /// </returns>
         public static object GetTip(Control element)
         {
             return element.GetValue(TipProperty);
         }
 
+        /// <summary>
+        /// Sets the value of the ToolTip.Tip attached property.
+        /// </summary>
+        /// <param name="element">The control to get the property from.</param>
+        /// <param name="value">The content to be displayed in the control's tooltip.</param>
         public static void SetTip(Control element, object value)
         {
             element.SetValue(TipProperty, value);
         }
 
+        /// <summary>
+        /// called when the <see cref="TipProperty"/> property changes on a control.
+        /// </summary>
+        /// <param name="e"></param>
         private static void TipChanged(PerspexPropertyChangedEventArgs e)
         {
             var control = (Control)e.Sender;
@@ -58,6 +98,10 @@ namespace Perspex.Controls
             }
         }
 
+        /// <summary>
+        /// Shows a tooltip for the specified control.
+        /// </summary>
+        /// <param name="control">The control.</param>
         private static void ShowToolTip(Control control)
         {
             if (control != null)
@@ -82,12 +126,22 @@ namespace Perspex.Controls
             }
         }
 
+        /// <summary>
+        /// Called when the pointer enters a control with an attached tooltip.
+        /// </summary>
+        /// <param name="sender">The event sender.</param>
+        /// <param name="e">The event args.</param>
         private static void ControlPointerEnter(object sender, PointerEventArgs e)
         {
             current = (Control)sender;
             show.OnNext(current);
         }
 
+        /// <summary>
+        /// Called when the pointer leaves a control with an attached tooltip.
+        /// </summary>
+        /// <param name="sender">The event sender.</param>
+        /// <param name="e">The event args.</param>
         private static void ControlPointerLeave(object sender, PointerEventArgs e)
         {
             var control = (Control)sender;