Enable XML doc.

25 files changed, 2045 insertions, 330 deletions

diff --git a/src/CSharp.Build.props b/src/CSharp.Build.props
index b12f4c6e..81d24ad1 100644
--- a/src/CSharp.Build.props
+++ b/src/CSharp.Build.props
@@ -5,7 +5,9 @@
 -->
 <Project>
   <PropertyGroup>
+    <CheckForOverflowUnderflow>true</CheckForOverflowUnderflow>
     <SignAssembly>true</SignAssembly>
     <AssemblyOriginatorKeyFile>$([System.IO.Path]::GetFullPath($(MSBuildThisFileDirectory)wix.snk))</AssemblyOriginatorKeyFile>
+    <NBGV_EmitThisAssemblyClass>false</NBGV_EmitThisAssemblyClass>
   </PropertyGroup>
 </Project>
diff --git a/src/Directory.Build.targets b/src/Directory.Build.targets
index dac7452a..cb988931 100644
--- a/src/Directory.Build.targets
+++ b/src/Directory.Build.targets
@@ -10,6 +10,11 @@
 -->
 <Project>
   <PropertyGroup>
+    <CreateDocumentation Condition=" '$(CreateDocumentationFile)'!='true' ">false</CreateDocumentation>
+    <DocumentationFile Condition=" '$(CreateDocumentationFile)'=='true' ">$(OutputPath)\$(AssemblyName).xml</DocumentationFile>
+  </PropertyGroup>
+
+  <PropertyGroup>
     <ReplacePackageReferences>true</ReplacePackageReferences>
     <TheSolutionPath Condition=" '$(NCrunch)'=='' ">$(SolutionPath)</TheSolutionPath>
     <TheSolutionPath Condition=" '$(NCrunch)'=='1' ">$(NCrunchOriginalSolutionPath)</TheSolutionPath>
@@ -45,4 +50,7 @@
 
     </When>
   </Choose>
+
+  <Import Project="Wix.Build.targets" Condition=" Exists('Wix.Build.targets') And '$(MSBuildProjectExtension)'=='.wixproj' " />
+  <Import Project="Custom.Build.targets" Condition=" Exists('Custom.Build.targets') " />
 </Project>
diff --git a/src/WixToolset.Mba.Core/BaseBootstrapperApplicationFactory.cs b/src/WixToolset.Mba.Core/BaseBootstrapperApplicationFactory.cs
index 264733ac..ad8a5dc0 100644
--- a/src/WixToolset.Mba.Core/BaseBootstrapperApplicationFactory.cs
+++ b/src/WixToolset.Mba.Core/BaseBootstrapperApplicationFactory.cs
@@ -5,8 +5,16 @@ namespace WixToolset.Mba.Core
     using System;
     using System.Runtime.InteropServices;
 
+    /// <summary>
+    /// Default implementation of <see cref="IBootstrapperApplicationFactory"/>.
+    /// </summary>
     public abstract class BaseBootstrapperApplicationFactory : IBootstrapperApplicationFactory
     {
+        /// <summary>
+        /// Default implementation of <see cref="IBootstrapperApplicationFactory.Create(IntPtr, IntPtr)"/>
+        /// </summary>
+        /// <param name="pArgs"></param>
+        /// <param name="pResults"></param>
         public void Create(IntPtr pArgs, IntPtr pResults)
         {
             InitializeFromCreateArgs(pArgs, out var engine, out var bootstrapperCommand);
@@ -15,8 +23,21 @@ namespace WixToolset.Mba.Core
             StoreBAInCreateResults(pResults, ba);
         }
 
+        /// <summary>
+        /// Called by <see cref="BaseBootstrapperApplicationFactory.Create(IntPtr, IntPtr)"/> to get the <see cref="IBootstrapperApplication"/>.
+        /// </summary>
+        /// <param name="engine">The bundle engine.</param>
+        /// <param name="bootstrapperCommand">Command information passed from the engine for the BA to perform.</param>
+        /// <returns>The <see cref="IBootstrapperApplication"/> for the bundle.</returns>
         protected abstract IBootstrapperApplication Create(IEngine engine, IBootstrapperCommand bootstrapperCommand);
 
+        /// <summary>
+        /// Initializes the native part of <see cref="WixToolset.Mba.Core"/>.
+        /// Most users should inherit from <see cref="BaseBootstrapperApplicationFactory"/> instead of calling this method.
+        /// </summary>
+        /// <param name="pArgs">The args struct given by the engine when initially creating the BA.</param>
+        /// <param name="engine">The bundle engine interface.</param>
+        /// <param name="bootstrapperCommand">The context of the current run of the bundle.</param>
         public static void InitializeFromCreateArgs(IntPtr pArgs, out IEngine engine, out IBootstrapperCommand bootstrapperCommand)
         {
             Command pCommand = new Command
@@ -28,6 +49,12 @@ namespace WixToolset.Mba.Core
             bootstrapperCommand = pCommand.GetBootstrapperCommand();
         }
 
+        /// <summary>
+        /// Registers the BA with the engine using the default mapping between the message based interface and the COM interface.
+        /// Most users should inherit from <see cref="BaseBootstrapperApplicationFactory"/> instead of calling this method.
+        /// </summary>
+        /// <param name="pResults">The results struct given by the engine when initially creating the BA</param>
+        /// <param name="ba">The <see cref="IBootstrapperApplication"/>.</param>
         public static void StoreBAInCreateResults(IntPtr pResults, IBootstrapperApplication ba)
         {
             BalUtil.StoreBAInCreateResults(pResults, ba);
diff --git a/src/WixToolset.Mba.Core/BootstrapperApplication.cs b/src/WixToolset.Mba.Core/BootstrapperApplication.cs
index 2d527427..759e76b1 100644
--- a/src/WixToolset.Mba.Core/BootstrapperApplication.cs
+++ b/src/WixToolset.Mba.Core/BootstrapperApplication.cs
@@ -34,347 +34,202 @@ namespace WixToolset.Mba.Core
             this.asyncExecution = true;
         }
 
-        /// <summary>
-        /// Fired when the engine is starting up the bootstrapper application.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<StartupEventArgs> Startup;
 
-        /// <summary>
-        /// Fired when the engine is shutting down the bootstrapper application.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ShutdownEventArgs> Shutdown;
 
-        /// <summary>
-        /// Fired when the system is shutting down or user is logging off.
-        /// </summary>
-        /// <remarks>
-        /// <para>To prevent shutting down or logging off, set <see cref="CancellableHResultEventArgs.Cancel"/> to
-        /// true; otherwise, set it to false.</para>
-        /// <para>By default setup will prevent shutting down or logging off between
-        /// <see cref="BootstrapperApplication.ApplyBegin"/> and <see cref="BootstrapperApplication.ApplyComplete"/>.
-        /// Derivatives can change this behavior by overriding <see cref="BootstrapperApplication.OnSystemShutdown"/>
-        /// or handling <see cref="BootstrapperApplication.SystemShutdown"/>.</para>
-        /// <para>If <see cref="SystemShutdownEventArgs.Reasons"/> contains <see cref="EndSessionReasons.Critical"/>
-        /// the bootstrapper cannot prevent the shutdown and only has a few seconds to save state or perform any other
-        /// critical operations before being closed by the operating system.</para>
-        /// <para>This event may be fired on a different thread.</para>
-        /// </remarks>
+        /// <inheritdoc/>
         public event EventHandler<SystemShutdownEventArgs> SystemShutdown;
 
-        /// <summary>
-        /// Fired when the overall detection phase has begun.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<DetectBeginEventArgs> DetectBegin;
 
-        /// <summary>
-        /// Fired when a forward compatible bundle is detected.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<DetectForwardCompatibleBundleEventArgs> DetectForwardCompatibleBundle;
 
-        /// <summary>
-        /// Fired when the update detection phase has begun.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<DetectUpdateBeginEventArgs> DetectUpdateBegin;
 
-        /// <summary>
-        /// Fired when the update detection has found a potential update candidate.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<DetectUpdateEventArgs> DetectUpdate;
 
-        /// <summary>
-        /// Fired when the update detection phase has completed.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<DetectUpdateCompleteEventArgs> DetectUpdateComplete;
 
-        /// <summary>
-        /// Fired when a related bundle has been detected for a bundle.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<DetectRelatedBundleEventArgs> DetectRelatedBundle;
 
-        /// <summary>
-        /// Fired when the detection for a specific package has begun.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<DetectPackageBeginEventArgs> DetectPackageBegin;
 
-        /// <summary>
-        /// Fired when a package was not detected but a package using the same provider key was.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<DetectCompatibleMsiPackageEventArgs> DetectCompatibleMsiPackage;
-
-        /// <summary>
-        /// Fired when a related MSI package has been detected for a package.
-        /// </summary>
+        
+        /// <inheritdoc/>
         public event EventHandler<DetectRelatedMsiPackageEventArgs> DetectRelatedMsiPackage;
 
-        /// <summary>
-        /// Fired when an MSP package detects a target MSI has been detected.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<DetectTargetMsiPackageEventArgs> DetectTargetMsiPackage;
 
-        /// <summary>
-        /// Fired when a feature in an MSI package has been detected.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<DetectMsiFeatureEventArgs> DetectMsiFeature;
 
-        /// <summary>
-        /// Fired when the detection for a specific package has completed.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<DetectPackageCompleteEventArgs> DetectPackageComplete;
 
-        /// <summary>
-        /// Fired when the detection phase has completed.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<DetectCompleteEventArgs> DetectComplete;
 
-        /// <summary>
-        /// Fired when the engine has begun planning the installation.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<PlanBeginEventArgs> PlanBegin;
 
-        /// <summary>
-        /// Fired when the engine has begun planning for a related bundle.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<PlanRelatedBundleEventArgs> PlanRelatedBundle;
 
-        /// <summary>
-        /// Fired when the engine has begun planning the installation of a specific package.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<PlanPackageBeginEventArgs> PlanPackageBegin;
 
-        /// <summary>
-        /// Fired when the engine plans a new, compatible package using the same provider key.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<PlanCompatibleMsiPackageBeginEventArgs> PlanCompatibleMsiPackageBegin;
 
-        /// <summary>
-        /// Fired when the engine has completed planning the installation of a specific package.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<PlanCompatibleMsiPackageCompleteEventArgs> PlanCompatibleMsiPackageComplete;
 
-        /// <summary>
-        /// Fired when the engine is about to plan the target MSI of a MSP package.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<PlanTargetMsiPackageEventArgs> PlanTargetMsiPackage;
 
-        /// <summary>
-        /// Fired when the engine is about to plan a feature in an MSI package.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<PlanMsiFeatureEventArgs> PlanMsiFeature;
 
-        /// <summary>
-        /// Fired when the engine is planning an MSI or MSP package.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<PlanMsiPackageEventArgs> PlanMsiPackage;
 
-        /// <summary>
-        /// Fired when the engine has completed planning the installation of a specific package.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<PlanPackageCompleteEventArgs> PlanPackageComplete;
 
-        /// <summary>
-        /// Fired when the engine has completed planning the installation.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<PlanCompleteEventArgs> PlanComplete;
 
-        /// <summary>
-        /// Fired when the engine has begun installing the bundle.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ApplyBeginEventArgs> ApplyBegin;
 
-        /// <summary>
-        /// Fired when the engine is about to start the elevated process.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ElevateBeginEventArgs> ElevateBegin;
 
-        /// <summary>
-        /// Fired when the engine has completed starting the elevated process.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ElevateCompleteEventArgs> ElevateComplete;
 
-        /// <summary>
-        /// Fired when the engine has changed progress for the bundle installation.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ProgressEventArgs> Progress;
 
-        /// <summary>
-        /// Fired when the engine has encountered an error.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ErrorEventArgs> Error;
 
-        /// <summary>
-        /// Fired when the engine has begun registering the location and visibility of the bundle.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<RegisterBeginEventArgs> RegisterBegin;
 
-        /// <summary>
-        /// Fired when the engine has completed registering the location and visibility of the bundle.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<RegisterCompleteEventArgs> RegisterComplete;
 
-        /// <summary>
-        /// Fired when the engine has begun removing the registration for the location and visibility of the bundle.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<UnregisterBeginEventArgs> UnregisterBegin;
 
-        /// <summary>
-        /// Fired when the engine has completed removing the registration for the location and visibility of the bundle.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<UnregisterCompleteEventArgs> UnregisterComplete;
 
-        /// <summary>
-        /// Fired when the engine has begun caching the installation sources.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<CacheBeginEventArgs> CacheBegin;
 
-        /// <summary>
-        /// Fired when the engine has begun caching a specific package.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<CachePackageBeginEventArgs> CachePackageBegin;
 
-        /// <summary>
-        /// Fired when the engine has begun acquiring the installation sources.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<CacheAcquireBeginEventArgs> CacheAcquireBegin;
 
-        /// <summary>
-        /// Fired when the engine has progress acquiring the installation sources.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<CacheAcquireProgressEventArgs> CacheAcquireProgress;
 
-        /// <summary>
-        /// Fired by the engine to allow the BA to change the source
-        /// using <see cref="M:Engine.SetLocalSource"/> or <see cref="M:Engine.SetDownloadSource"/>.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ResolveSourceEventArgs> ResolveSource;
 
-        /// <summary>
-        /// Fired when the engine has completed the acquisition of the installation sources.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<CacheAcquireCompleteEventArgs> CacheAcquireComplete;
 
-        /// <summary>
-        /// Fired when the engine begins the verification of the acquired installation sources.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<CacheVerifyBeginEventArgs> CacheVerifyBegin;
 
-        /// <summary>
-        /// Fired when the engine complete the verification of the acquired installation sources.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<CacheVerifyCompleteEventArgs> CacheVerifyComplete;
 
-        /// <summary>
-        /// Fired when the engine has completed caching a specific package.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<CachePackageCompleteEventArgs> CachePackageComplete;
 
-        /// <summary>
-        /// Fired after the engine has cached the installation sources.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<CacheCompleteEventArgs> CacheComplete;
 
-        /// <summary>
-        /// Fired when the engine has begun installing packages.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ExecuteBeginEventArgs> ExecuteBegin;
 
-        /// <summary>
-        /// Fired when the engine has begun installing a specific package.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ExecutePackageBeginEventArgs> ExecutePackageBegin;
 
-        /// <summary>
-        /// Fired when the engine executes one or more patches targeting a product.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ExecutePatchTargetEventArgs> ExecutePatchTarget;
 
-        /// <summary>
-        /// Fired when Windows Installer sends an installation message.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ExecuteMsiMessageEventArgs> ExecuteMsiMessage;
 
-        /// <summary>
-        /// Fired when Windows Installer sends a files in use installation message.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ExecuteFilesInUseEventArgs> ExecuteFilesInUse;
 
-        /// <summary>
-        /// Fired when the engine has completed installing a specific package.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ExecutePackageCompleteEventArgs> ExecutePackageComplete;
 
-        /// <summary>
-        /// Fired when the engine has completed installing packages.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ExecuteCompleteEventArgs> ExecuteComplete;
 
-        /// <summary>
-        /// Fired when the engine has completed installing the bundle.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ApplyCompleteEventArgs> ApplyComplete;
 
-        /// <summary>
-        /// Fired by the engine while executing on payload.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<ExecuteProgressEventArgs> ExecuteProgress;
 
-        /// <summary>
-        /// Fired when the engine is about to launch the preapproved executable.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<LaunchApprovedExeBeginEventArgs> LaunchApprovedExeBegin;
 
-        /// <summary>
-        /// Fired when the engine has completed launching the preapproved executable.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<LaunchApprovedExeCompleteEventArgs> LaunchApprovedExeComplete;
 
-        /// <summary>
-        /// Fired when the engine is about to begin an MSI transaction.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<BeginMsiTransactionBeginEventArgs> BeginMsiTransactionBegin;
 
-        /// <summary>
-        /// Fired when the engine has completed beginning an MSI transaction.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<BeginMsiTransactionCompleteEventArgs> BeginMsiTransactionComplete;
 
-        /// <summary>
-        /// Fired when the engine is about to commit an MSI transaction.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<CommitMsiTransactionBeginEventArgs> CommitMsiTransactionBegin;
 
-        /// <summary>
-        /// Fired when the engine has completed comitting an MSI transaction.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<CommitMsiTransactionCompleteEventArgs> CommitMsiTransactionComplete;
 
-        /// <summary>
-        /// Fired when the engine is about to rollback an MSI transaction.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<RollbackMsiTransactionBeginEventArgs> RollbackMsiTransactionBegin;
 
-        /// <summary>
-        /// Fired when the engine has completed rolling back an MSI transaction.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<RollbackMsiTransactionCompleteEventArgs> RollbackMsiTransactionComplete;
 
-        /// <summary>
-        /// Fired when the engine is about to pause Windows automatic updates.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<PauseAutomaticUpdatesBeginEventArgs> PauseAutomaticUpdatesBegin;
 
-        /// <summary>
-        /// Fired when the engine has completed pausing Windows automatic updates.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<PauseAutomaticUpdatesCompleteEventArgs> PauseAutomaticUpdatesComplete;
 
-        /// <summary>
-        /// Fired when the engine is about to take a system restore point.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<SystemRestorePointBeginEventArgs> SystemRestorePointBegin;
 
-        /// <summary>
-        /// Fired when the engine has completed taking a system restore point.
-        /// </summary>
+        /// <inheritdoc/>
         public event EventHandler<SystemRestorePointCompleteEventArgs> SystemRestorePointComplete;
 
         /// <summary>
@@ -383,7 +238,7 @@ namespace WixToolset.Mba.Core
         protected abstract void Run();
 
         /// <summary>
-        /// Called by the engine on startup of the bootstrapper application.
+        /// Called by the engine, raises the <see cref="Startup"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnStartup(StartupEventArgs args)
@@ -410,7 +265,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine to uninitialize the BA.
+        /// Called by the engine, raises the <see cref="Shutdown"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnShutdown(ShutdownEventArgs args)
@@ -423,21 +278,9 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the system is shutting down or the user is logging off.
+        /// Called by the engine, raises the <see cref="SystemShutdown"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
-        /// <remarks>
-        /// <para>To prevent shutting down or logging off, set <see cref="CancellableHResultEventArgs.Cancel"/> to
-        /// true; otherwise, set it to false.</para>
-        /// <para>By default setup will prevent shutting down or logging off between
-        /// <see cref="BootstrapperApplication.ApplyBegin"/> and <see cref="BootstrapperApplication.ApplyComplete"/>.
-        /// Derivatives can change this behavior by overriding <see cref="BootstrapperApplication.OnSystemShutdown"/>
-        /// or handling <see cref="BootstrapperApplication.SystemShutdown"/>.</para>
-        /// <para>If <see cref="SystemShutdownEventArgs.Reasons"/> contains <see cref="EndSessionReasons.Critical"/>
-        /// the bootstrapper cannot prevent the shutdown and only has a few seconds to save state or perform any other
-        /// critical operations before being closed by the operating system.</para>
-        /// <para>This method may be called on a different thread.</para>
-        /// </remarks>
         protected virtual void OnSystemShutdown(SystemShutdownEventArgs args)
         {
             EventHandler<SystemShutdownEventArgs> handler = this.SystemShutdown;
@@ -454,7 +297,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the overall detection phase has begun.
+        /// Called by the engine, raises the <see cref="DetectBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnDetectBegin(DetectBeginEventArgs args)
@@ -467,7 +310,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the update detection phase has begun.
+        /// Called by the engine, raises the <see cref="DetectForwardCompatibleBundle"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnDetectForwardCompatibleBundle(DetectForwardCompatibleBundleEventArgs args)
@@ -480,7 +323,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the update detection phase has begun.
+        /// Called by the engine, raises the <see cref="DetectUpdateBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnDetectUpdateBegin(DetectUpdateBeginEventArgs args)
@@ -493,7 +336,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Fired when the update detection has found a potential update candidate.
+        /// Called by the engine, raises the <see cref="DetectUpdate"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnDetectUpdate(DetectUpdateEventArgs args)
@@ -506,7 +349,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the update detection phase has completed.
+        /// Called by the engine, raises the <see cref="DetectUpdateComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnDetectUpdateComplete(DetectUpdateCompleteEventArgs args)
@@ -519,7 +362,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when a related bundle has been detected for a bundle.
+        /// Called by the engine, raises the <see cref="DetectRelatedBundle"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnDetectRelatedBundle(DetectRelatedBundleEventArgs args)
@@ -532,7 +375,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the detection for a specific package has begun.
+        /// Called by the engine, raises the <see cref="DetectPackageBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnDetectPackageBegin(DetectPackageBeginEventArgs args)
@@ -545,7 +388,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when a package was not detected but a package using the same provider key was.
+        /// Called by the engine, raises the <see cref="DetectCompatibleMsiPackage"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnDetectCompatibleMsiPackage(DetectCompatibleMsiPackageEventArgs args)
@@ -558,7 +401,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when a related MSI package has been detected for a package.
+        /// Called by the engine, raises the <see cref="DetectRelatedMsiPackage"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnDetectRelatedMsiPackage(DetectRelatedMsiPackageEventArgs args)
@@ -571,7 +414,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when an MSP package detects a target MSI has been detected.
+        /// Called by the engine, raises the <see cref="DetectTargetMsiPackage"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnDetectTargetMsiPackage(DetectTargetMsiPackageEventArgs args)
@@ -584,7 +427,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when an MSI feature has been detected for a package.
+        /// Called by the engine, raises the <see cref="DetectMsiFeature"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnDetectMsiFeature(DetectMsiFeatureEventArgs args)
@@ -597,7 +440,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the detection for a specific package has completed.
+        /// Called by the engine, raises the <see cref="DetectPackageComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnDetectPackageComplete(DetectPackageCompleteEventArgs args)
@@ -610,7 +453,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the detection phase has completed.
+        /// Called by the engine, raises the <see cref="DetectComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnDetectComplete(DetectCompleteEventArgs args)
@@ -623,7 +466,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has begun planning the installation.
+        /// Called by the engine, raises the <see cref="PlanBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnPlanBegin(PlanBeginEventArgs args)
@@ -636,7 +479,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has begun planning for a prior bundle.
+        /// Called by the engine, raises the <see cref="PlanRelatedBundle"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnPlanRelatedBundle(PlanRelatedBundleEventArgs args)
@@ -649,7 +492,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has begun planning the installation of a specific package.
+        /// Called by the engine, raises the <see cref="PlanPackageBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnPlanPackageBegin(PlanPackageBeginEventArgs args)
@@ -662,7 +505,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine plans a new, compatible package using the same provider key.
+        /// Called by the engine, raises the <see cref="PlanCompatibleMsiPackageBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnPlanCompatibleMsiPackageBegin(PlanCompatibleMsiPackageBeginEventArgs args)
@@ -675,7 +518,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has completed planning the installation of a specific package.
+        /// Called by the engine, raises the <see cref="PlanCompatibleMsiPackageComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnPlanCompatibleMsiPackageComplete(PlanCompatibleMsiPackageCompleteEventArgs args)
@@ -688,7 +531,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine is about to plan the target MSI of a MSP package.
+        /// Called by the engine, raises the <see cref="PlanTargetMsiPackage"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnPlanTargetMsiPackage(PlanTargetMsiPackageEventArgs args)
@@ -701,7 +544,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine is about to plan an MSI feature of a specific package.
+        /// Called by the engine, raises the <see cref="PlanMsiFeature"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnPlanMsiFeature(PlanMsiFeatureEventArgs args)
@@ -714,7 +557,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine is planning an MSI or MSP package.
+        /// Called by the engine, raises the <see cref="PlanMsiPackage"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnPlanMsiPackage(PlanMsiPackageEventArgs args)
@@ -727,7 +570,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when then engine has completed planning the installation of a specific package.
+        /// Called by the engine, raises the <see cref="PlanPackageComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnPlanPackageComplete(PlanPackageCompleteEventArgs args)
@@ -740,7 +583,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has completed planning the installation.
+        /// Called by the engine, raises the <see cref="PlanComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnPlanComplete(PlanCompleteEventArgs args)
@@ -753,7 +596,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has begun installing the bundle.
+        /// Called by the engine, raises the <see cref="ApplyBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnApplyBegin(ApplyBeginEventArgs args)
@@ -766,7 +609,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine is about to start the elevated process.
+        /// Called by the engine, raises the <see cref="ElevateBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnElevateBegin(ElevateBeginEventArgs args)
@@ -779,7 +622,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has completed starting the elevated process.
+        /// Called by the engine, raises the <see cref="ElevateComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnElevateComplete(ElevateCompleteEventArgs args)
@@ -792,7 +635,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has changed progress for the bundle installation.
+        /// Called by the engine, raises the <see cref="Progress"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnProgress(ProgressEventArgs args)
@@ -805,7 +648,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has encountered an error.
+        /// Called by the engine, raises the <see cref="Error"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnError(ErrorEventArgs args)
@@ -818,7 +661,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has begun registering the location and visibility of the bundle.
+        /// Called by the engine, raises the <see cref="RegisterBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnRegisterBegin(RegisterBeginEventArgs args)
@@ -831,7 +674,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has completed registering the location and visilibity of the bundle.
+        /// Called by the engine, raises the <see cref="RegisterComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnRegisterComplete(RegisterCompleteEventArgs args)
@@ -844,7 +687,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has begun removing the registration for the location and visibility of the bundle.
+        /// Called by the engine, raises the <see cref="UnregisterBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnUnregisterBegin(UnregisterBeginEventArgs args)
@@ -857,7 +700,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has completed removing the registration for the location and visibility of the bundle.
+        /// Called by the engine, raises the <see cref="UnregisterComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnUnregisterComplete(UnregisterCompleteEventArgs args)
@@ -870,7 +713,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine begins to cache the installation sources.
+        /// Called by the engine, raises the <see cref="CacheBegin"/> event.
         /// </summary>
         /// <param name="args"></param>
         protected virtual void OnCacheBegin(CacheBeginEventArgs args)
@@ -883,7 +726,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine when it begins to cache a specific package.
+        /// Called by the engine, raises the <see cref="CachePackageBegin"/> event.
         /// </summary>
         /// <param name="args"></param>
         protected virtual void OnCachePackageBegin(CachePackageBeginEventArgs args)
@@ -896,7 +739,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine begins to cache the container or payload.
+        /// Called by the engine, raises the <see cref="CacheAcquireBegin"/> event.
         /// </summary>
         /// <param name="args"></param>
         protected virtual void OnCacheAcquireBegin(CacheAcquireBeginEventArgs args)
@@ -909,7 +752,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has progressed on caching the container or payload.
+        /// Called by the engine, raises the <see cref="CacheAcquireProgress"/> event.
         /// </summary>
         /// <param name="args"></param>
         protected virtual void OnCacheAcquireProgress(CacheAcquireProgressEventArgs args)
@@ -922,8 +765,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine to allow the BA to change the source
-        /// using <see cref="M:Engine.SetLocalSource"/> or <see cref="M:Engine.SetDownloadSource"/>.
+        /// Called by the engine, raises the <see cref="ResolveSource"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnResolveSource(ResolveSourceEventArgs args)
@@ -936,7 +778,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine completes caching of the container or payload.
+        /// Called by the engine, raises the <see cref="CacheAcquireComplete"/> event.
         /// </summary>
         /// <param name="args"></param>
         protected virtual void OnCacheAcquireComplete(CacheAcquireCompleteEventArgs args)
@@ -949,7 +791,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has started verify the payload.
+        /// Called by the engine, raises the <see cref="CacheVerifyBegin"/> event.
         /// </summary>
         /// <param name="args"></param>
         protected virtual void OnCacheVerifyBegin(CacheVerifyBeginEventArgs args)
@@ -962,7 +804,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine completes verification of the payload.
+        /// Called by the engine, raises the <see cref="CacheVerifyComplete"/> event.
         /// </summary>
         /// <param name="args"></param>
         protected virtual void OnCacheVerifyComplete(CacheVerifyCompleteEventArgs args)
@@ -975,7 +817,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine completes caching a specific package.
+        /// Called by the engine, raises the <see cref="CachePackageComplete"/> event.
         /// </summary>
         /// <param name="args"></param>
         protected virtual void OnCachePackageComplete(CachePackageCompleteEventArgs args)
@@ -988,7 +830,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called after the engine has cached the installation sources.
+        /// Called by the engine, raises the <see cref="CacheComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnCacheComplete(CacheCompleteEventArgs args)
@@ -1001,7 +843,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has begun installing packages.
+        /// Called by the engine, raises the <see cref="ExecuteBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnExecuteBegin(ExecuteBeginEventArgs args)
@@ -1014,7 +856,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has begun installing a specific package.
+        /// Called by the engine, raises the <see cref="ExecutePackageBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnExecutePackageBegin(ExecutePackageBeginEventArgs args)
@@ -1027,7 +869,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine executes one or more patches targeting a product.
+        /// Called by the engine, raises the <see cref="ExecutePatchTarget"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnExecutePatchTarget(ExecutePatchTargetEventArgs args)
@@ -1040,7 +882,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when Windows Installer sends an installation message.
+        /// Called by the engine, raises the <see cref="ExecuteMsiMessage"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnExecuteMsiMessage(ExecuteMsiMessageEventArgs args)
@@ -1053,7 +895,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when Windows Installer sends a file in use installation message.
+        /// Called by the engine, raises the <see cref="ExecuteFilesInUse"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnExecuteFilesInUse(ExecuteFilesInUseEventArgs args)
@@ -1066,7 +908,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has completed installing a specific package.
+        /// Called by the engine, raises the <see cref="ExecutePackageComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnExecutePackageComplete(ExecutePackageCompleteEventArgs args)
@@ -1079,7 +921,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has completed installing packages.
+        /// Called by the engine, raises the <see cref="ExecuteComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnExecuteComplete(ExecuteCompleteEventArgs args)
@@ -1092,7 +934,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called when the engine has completed installing the bundle.
+        /// Called by the engine, raises the <see cref="ApplyComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnApplyComplete(ApplyCompleteEventArgs args)
@@ -1105,7 +947,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine while executing on payload.
+        /// Called by the engine, raises the <see cref="ExecuteProgress"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnExecuteProgress(ExecuteProgressEventArgs args)
@@ -1118,7 +960,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine before trying to launch the preapproved executable.
+        /// Called by the engine, raises the <see cref="LaunchApprovedExeBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnLaunchApprovedExeBegin(LaunchApprovedExeBeginEventArgs args)
@@ -1131,7 +973,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine after trying to launch the preapproved executable.
+        /// Called by the engine, raises the <see cref="LaunchApprovedExeComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnLaunchApprovedExeComplete(LaunchApprovedExeCompleteEventArgs args)
@@ -1144,7 +986,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine before beginning an MSI transaction.
+        /// Called by the engine, raises the <see cref="BeginMsiTransactionBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnBeginMsiTransactionBegin(BeginMsiTransactionBeginEventArgs args)
@@ -1157,7 +999,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine after beginning an MSI transaction.
+        /// Called by the engine, raises the <see cref="BeginMsiTransactionComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnBeginMsiTransactionComplete(BeginMsiTransactionCompleteEventArgs args)
@@ -1170,7 +1012,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine before committing an MSI transaction.
+        /// Called by the engine, raises the <see cref="CommitMsiTransactionBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnCommitMsiTransactionBegin(CommitMsiTransactionBeginEventArgs args)
@@ -1183,7 +1025,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine after committing an MSI transaction.
+        /// Called by the engine, raises the <see cref="CommitMsiTransactionComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnCommitMsiTransactionComplete(CommitMsiTransactionCompleteEventArgs args)
@@ -1196,7 +1038,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine before rolling back an MSI transaction.
+        /// Called by the engine, raises the <see cref="RollbackMsiTransactionBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnRollbackMsiTransactionBegin(RollbackMsiTransactionBeginEventArgs args)
@@ -1209,7 +1051,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine after rolling back an MSI transaction.
+        /// Called by the engine, raises the <see cref="RollbackMsiTransactionComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnRollbackMsiTransactionComplete(RollbackMsiTransactionCompleteEventArgs args)
@@ -1222,7 +1064,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine before pausing Windows automatic updates.
+        /// Called by the engine, raises the <see cref="PauseAutomaticUpdatesBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnPauseAutomaticUpdatesBegin(PauseAutomaticUpdatesBeginEventArgs args)
@@ -1235,7 +1077,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine after pausing Windows automatic updates.
+        /// Called by the engine, raises the <see cref="PauseAutomaticUpdatesComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnPauseAutomaticUpdatesComplete(PauseAutomaticUpdatesCompleteEventArgs args)
@@ -1248,7 +1090,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine before taking a system restore point.
+        /// Called by the engine, raises the <see cref="SystemRestorePointBegin"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnSystemRestorePointBegin(SystemRestorePointBeginEventArgs args)
@@ -1261,7 +1103,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Called by the engine after taking a system restore point.
+        /// Called by the engine, raises the <see cref="SystemRestorePointComplete"/> event.
         /// </summary>
         /// <param name="args">Additional arguments for this event.</param>
         protected virtual void OnSystemRestorePointComplete(SystemRestorePointCompleteEventArgs args)
diff --git a/src/WixToolset.Mba.Core/BootstrapperApplicationData.cs b/src/WixToolset.Mba.Core/BootstrapperApplicationData.cs
index 05672f1b..739a08bb 100644
--- a/src/WixToolset.Mba.Core/BootstrapperApplicationData.cs
+++ b/src/WixToolset.Mba.Core/BootstrapperApplicationData.cs
@@ -6,12 +6,29 @@ namespace WixToolset.Mba.Core
     using System.IO;
     using System.Xml.XPath;
 
+    /// <summary>
+    /// Utility class for reading BootstrapperApplicationData.xml.
+    /// </summary>
     public class BootstrapperApplicationData : IBootstrapperApplicationData
     {
+        /// <summary>
+        /// 
+        /// </summary>
         public const string DefaultFileName = "BootstrapperApplicationData.xml";
+
+        /// <summary>
+        /// 
+        /// </summary>
         public const string XMLNamespace = "http://wixtoolset.org/schemas/v4/BootstrapperApplicationData";
 
+        /// <summary>
+        /// The default path of where the BA was extracted to.
+        /// </summary>
         public static readonly DirectoryInfo DefaultFolder;
+
+        /// <summary>
+        /// The default path to BootstrapperApplicationData.xml.
+        /// </summary>
         public static readonly FileInfo DefaultFile;
 
         static BootstrapperApplicationData()
@@ -20,12 +37,21 @@ namespace WixToolset.Mba.Core
             DefaultFile = new FileInfo(Path.Combine(DefaultFolder.FullName, DefaultFileName));
         }
 
+        /// <inheritdoc/>
         public FileInfo BADataFile { get; private set; }
 
+        /// <inheritdoc/>
         public IBundleInfo Bundle { get; private set; }
 
+        /// <summary>
+        /// Uses the default location for BootstrapperApplicationData.xml.
+        /// </summary>
         public BootstrapperApplicationData() : this(DefaultFile) { }
 
+        /// <summary>
+        /// Uses the given file for BootstrapperApplicationData.xml.
+        /// </summary>
+        /// <param name="baDataFile"></param>
         public BootstrapperApplicationData(FileInfo baDataFile)
         {
             this.BADataFile = baDataFile;
@@ -36,6 +62,12 @@ namespace WixToolset.Mba.Core
             }
         }
 
+        /// <summary>
+        /// Utility method for parsing BootstrapperApplicationData.xml.
+        /// </summary>
+        /// <param name="node"></param>
+        /// <param name="attributeName"></param>
+        /// <returns></returns>
         public static string GetAttribute(XPathNavigator node, string attributeName)
         {
             XPathNavigator attribute = node.SelectSingleNode("@" + attributeName);
@@ -48,6 +80,12 @@ namespace WixToolset.Mba.Core
             return attribute.Value;
         }
 
+        /// <summary>
+        /// Utility method for parsing BootstrapperApplicationData.xml.
+        /// </summary>
+        /// <param name="node"></param>
+        /// <param name="attributeName"></param>
+        /// <returns></returns>
         public static bool? GetYesNoAttribute(XPathNavigator node, string attributeName)
         {
             string attributeValue = GetAttribute(node, attributeName);
diff --git a/src/WixToolset.Mba.Core/BootstrapperCommand.cs b/src/WixToolset.Mba.Core/BootstrapperCommand.cs
index 42d19bf9..65dde0f4 100644
--- a/src/WixToolset.Mba.Core/BootstrapperCommand.cs
+++ b/src/WixToolset.Mba.Core/BootstrapperCommand.cs
@@ -6,10 +6,28 @@ namespace WixToolset.Mba.Core
     using System.ComponentModel;
     using System.Runtime.InteropServices;
 
+    /// <summary>
+    /// Default implementation of <see cref="IBootstrapperCommand"/>.
+    /// </summary>
     public sealed class BootstrapperCommand : IBootstrapperCommand
     {
         private readonly string commandLine;
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="action"></param>
+        /// <param name="display"></param>
+        /// <param name="restart"></param>
+        /// <param name="commandLine"></param>
+        /// <param name="cmdShow"></param>
+        /// <param name="resume"></param>
+        /// <param name="splashScreen"></param>
+        /// <param name="relation"></param>
+        /// <param name="passthrough"></param>
+        /// <param name="layoutDirectory"></param>
+        /// <param name="bootstrapperWorkingFolder"></param>
+        /// <param name="bootstrapperApplicationDataPath"></param>
         public BootstrapperCommand(
             LaunchAction action,
             Display display,
@@ -38,28 +56,40 @@ namespace WixToolset.Mba.Core
             this.BootstrapperApplicationDataPath = bootstrapperApplicationDataPath;
         }
 
+        /// <inheritdoc/>
         public LaunchAction Action { get; }
 
+        /// <inheritdoc/>
         public Display Display { get; }
 
+        /// <inheritdoc/>
         public Restart Restart { get; }
 
+        /// <inheritdoc/>
         public string[] CommandLineArgs => GetCommandLineArgs(this.commandLine);
 
+        /// <inheritdoc/>
         public int CmdShow { get; }
 
+        /// <inheritdoc/>
         public ResumeType Resume { get; }
 
+        /// <inheritdoc/>
         public IntPtr SplashScreen { get; }
 
+        /// <inheritdoc/>
         public RelationType Relation { get; }
 
+        /// <inheritdoc/>
         public bool Passthrough { get; }
 
+        /// <inheritdoc/>
         public string LayoutDirectory { get; }
 
+        /// <inheritdoc/>
         public string BootstrapperWorkingFolder { get; }
 
+        /// <inheritdoc/>
         public string BootstrapperApplicationDataPath { get; }
 
         /// <summary>
diff --git a/src/WixToolset.Mba.Core/BundleInfo.cs b/src/WixToolset.Mba.Core/BundleInfo.cs
index e1a56878..3d5d535d 100644
--- a/src/WixToolset.Mba.Core/BundleInfo.cs
+++ b/src/WixToolset.Mba.Core/BundleInfo.cs
@@ -8,11 +8,21 @@ namespace WixToolset.Mba.Core
     using System.Xml;
     using System.Xml.XPath;
 
+    /// <summary>
+    /// Default implementation of <see cref="IBundleInfo"/>.
+    /// </summary>
     public class BundleInfo : IBundleInfo
     {
+        /// <inheritdoc/>
         public bool PerMachine { get; internal set; }
+
+        /// <inheritdoc/>
         public string Name { get; internal set; }
+
+        /// <inheritdoc/>
         public string LogVariable { get; internal set; }
+
+        /// <inheritdoc/>
         public IDictionary<string, IPackageInfo> Packages { get; internal set; }
 
         internal BundleInfo()
@@ -20,6 +30,7 @@ namespace WixToolset.Mba.Core
             this.Packages = new Dictionary<string, IPackageInfo>();
         }
 
+        /// <inheritdoc/>
         public IPackageInfo AddRelatedBundleAsPackage(DetectRelatedBundleEventArgs e)
         {
             var package = PackageInfo.GetRelatedBundleAsPackage(e.ProductCode, e.RelationType, e.PerMachine, e.Version);
@@ -27,6 +38,11 @@ namespace WixToolset.Mba.Core
             return package;
         }
 
+        /// <summary>
+        /// Parses BA manifest from the given stream.
+        /// </summary>
+        /// <param name="stream"></param>
+        /// <returns></returns>
         public static IBundleInfo ParseBundleFromStream(Stream stream)
         {
             XPathDocument manifest = new XPathDocument(stream);
@@ -34,6 +50,11 @@ namespace WixToolset.Mba.Core
             return ParseBundleFromXml(root);
         }
 
+        /// <summary>
+        /// Parses BA manifest from the given <see cref="XPathNavigator"/>.
+        /// </summary>
+        /// <param name="root">The root of the BA manifest.</param>
+        /// <returns></returns>
         public static IBundleInfo ParseBundleFromXml(XPathNavigator root)
         {
             BundleInfo bundle = new BundleInfo();
diff --git a/src/WixToolset.Mba.Core/Engine.cs b/src/WixToolset.Mba.Core/Engine.cs
index c6570f9d..d5c43a53 100644
--- a/src/WixToolset.Mba.Core/Engine.cs
+++ b/src/WixToolset.Mba.Core/Engine.cs
@@ -9,7 +9,7 @@ namespace WixToolset.Mba.Core
     using System.Text;
 
     /// <summary>
-    /// Container class for the <see cref="IBootstrapperEngine"/> interface.
+    /// Default implementation of <see cref="IEngine"/>.
     /// </summary>
     public sealed class Engine : IEngine
     {
@@ -28,6 +28,7 @@ namespace WixToolset.Mba.Core
             this.engine = engine;
         }
 
+        /// <inheritdoc/>
         public int PackageCount
         {
             get
@@ -39,22 +40,26 @@ namespace WixToolset.Mba.Core
             }
         }
 
+        /// <inheritdoc/>
         public void Apply(IntPtr hwndParent)
         {
             this.engine.Apply(hwndParent);
         }
 
+        /// <inheritdoc/>
         public void CloseSplashScreen()
         {
             this.engine.CloseSplashScreen();
         }
 
+        /// <inheritdoc/>
         public int CompareVersions(string version1, string version2)
         {
             this.engine.CompareVersions(version1, version2, out var result);
             return result;
         }
 
+        /// <inheritdoc/>
         public bool ContainsVariable(string name)
         {
             int capacity = 0;
@@ -62,16 +67,19 @@ namespace WixToolset.Mba.Core
             return NativeMethods.E_NOTFOUND != ret;
         }
 
+        /// <inheritdoc/>
         public void Detect()
         {
             this.Detect(IntPtr.Zero);
         }
 
+        /// <inheritdoc/>
         public void Detect(IntPtr hwndParent)
         {
             this.engine.Detect(hwndParent);
         }
 
+        /// <inheritdoc/>
         public bool Elevate(IntPtr hwndParent)
         {
             int ret = this.engine.Elevate(hwndParent);
@@ -90,6 +98,7 @@ namespace WixToolset.Mba.Core
             }
         }
 
+        /// <inheritdoc/>
         public string EscapeString(string input)
         {
             int capacity = InitialBufferSize;
@@ -111,6 +120,7 @@ namespace WixToolset.Mba.Core
             return sb.ToString();
         }
 
+        /// <inheritdoc/>
         public bool EvaluateCondition(string condition)
         {
             bool value;
@@ -119,6 +129,7 @@ namespace WixToolset.Mba.Core
             return value;
         }
 
+        /// <inheritdoc/>
         public string FormatString(string format)
         {
             int capacity = InitialBufferSize;
@@ -140,6 +151,7 @@ namespace WixToolset.Mba.Core
             return sb.ToString();
         }
 
+        /// <inheritdoc/>
         public long GetVariableNumeric(string name)
         {
             int ret = this.engine.GetVariableNumeric(name, out long value);
@@ -151,6 +163,7 @@ namespace WixToolset.Mba.Core
             return value;
         }
 
+        /// <inheritdoc/>
         public SecureString GetVariableSecureString(string name)
         {
             var pUniString = this.getStringVariable(name, out var length);
@@ -167,6 +180,7 @@ namespace WixToolset.Mba.Core
             }
         }
 
+        /// <inheritdoc/>
         public string GetVariableString(string name)
         {
             int length;
@@ -184,6 +198,7 @@ namespace WixToolset.Mba.Core
             }
         }
 
+        /// <inheritdoc/>
         public string GetVariableVersion(string name)
         {
             int length;
@@ -201,46 +216,55 @@ namespace WixToolset.Mba.Core
             }
         }
 
+        /// <inheritdoc/>
         public void LaunchApprovedExe(IntPtr hwndParent, string approvedExeForElevationId, string arguments)
         {
             this.LaunchApprovedExe(hwndParent, approvedExeForElevationId, arguments, 0);
         }
 
+        /// <inheritdoc/>
         public void LaunchApprovedExe(IntPtr hwndParent, string approvedExeForElevationId, string arguments, int waitForInputIdleTimeout)
         {
             this.engine.LaunchApprovedExe(hwndParent, approvedExeForElevationId, arguments, waitForInputIdleTimeout);
         }
+        /// <inheritdoc/>
 
         public void Log(LogLevel level, string message)
         {
             this.engine.Log(level, message);
         }
 
+        /// <inheritdoc/>
         public void Plan(LaunchAction action)
         {
             this.engine.Plan(action);
         }
 
+        /// <inheritdoc/>
         public void SetUpdate(string localSource, string downloadSource, long size, UpdateHashType hashType, byte[] hash)
         {
             this.engine.SetUpdate(localSource, downloadSource, size, hashType, hash, null == hash ? 0 : hash.Length);
         }
 
+        /// <inheritdoc/>
         public void SetLocalSource(string packageOrContainerId, string payloadId, string path)
         {
             this.engine.SetLocalSource(packageOrContainerId, payloadId, path);
         }
 
+        /// <inheritdoc/>
         public void SetDownloadSource(string packageOrContainerId, string payloadId, string url, string user, string password)
         {
             this.engine.SetDownloadSource(packageOrContainerId, payloadId, url, user, password);
         }
 
+        /// <inheritdoc/>
         public void SetVariableNumeric(string name, long value)
         {
             this.engine.SetVariableNumeric(name, value);
         }
 
+        /// <inheritdoc/>
         public void SetVariableString(string name, SecureString value, bool formatted)
         {
             IntPtr pValue = Marshal.SecureStringToCoTaskMemUnicode(value);
@@ -254,6 +278,7 @@ namespace WixToolset.Mba.Core
             }
         }
 
+        /// <inheritdoc/>
         public void SetVariableString(string name, string value, bool formatted)
         {
             IntPtr pValue = Marshal.StringToCoTaskMemUni(value);
@@ -267,6 +292,7 @@ namespace WixToolset.Mba.Core
             }
         }
 
+        /// <inheritdoc/>
         public void SetVariableVersion(string name, string value)
         {
             IntPtr pValue = Marshal.StringToCoTaskMemUni(value);
@@ -280,6 +306,7 @@ namespace WixToolset.Mba.Core
             }
         }
 
+        /// <inheritdoc/>
         public int SendEmbeddedError(int errorCode, string message, int uiHint)
         {
             int result = 0;
@@ -287,6 +314,7 @@ namespace WixToolset.Mba.Core
             return result;
         }
 
+        /// <inheritdoc/>
         public int SendEmbeddedProgress(int progressPercentage, int overallPercentage)
         {
             int result = 0;
@@ -294,6 +322,7 @@ namespace WixToolset.Mba.Core
             return result;
         }
 
+        /// <inheritdoc/>
         public void Quit(int exitCode)
         {
             this.engine.Quit(exitCode);
@@ -423,6 +452,11 @@ namespace WixToolset.Mba.Core
             return value;
         }
 
+        /// <summary>
+        /// Utility method for converting a <see cref="Version"/> into a <see cref="long"/>.
+        /// </summary>
+        /// <param name="version"></param>
+        /// <returns></returns>
         public static long VersionToLong(Version version)
         {
             // In Windows, each version component has a max value of 65535,
@@ -435,6 +469,11 @@ namespace WixToolset.Mba.Core
             return major | minor | build | revision;
         }
 
+        /// <summary>
+        /// Utility method for converting a <see cref="long"/> into a <see cref="Version"/>.
+        /// </summary>
+        /// <param name="version"></param>
+        /// <returns></returns>
         public static Version LongToVersion(long version)
         {
             int major = (int)((version & ((long)0xffff << 48)) >> 48);
@@ -446,7 +485,7 @@ namespace WixToolset.Mba.Core
         }
 
         /// <summary>
-        /// Verifies that VersionVariables can pass on the given Version to the engine.
+        /// Verifies that Version can be represented in a <see cref="long"/>.
         /// If the Build or Revision fields are undefined, they are set to zero.
         /// </summary>
         public static Version NormalizeVersion(Version version)
diff --git a/src/WixToolset.Mba.Core/EventArgs.cs b/src/WixToolset.Mba.Core/EventArgs.cs
index b52b893a..4e59fd6f 100644
--- a/src/WixToolset.Mba.Core/EventArgs.cs
+++ b/src/WixToolset.Mba.Core/EventArgs.cs
@@ -163,7 +163,7 @@ namespace WixToolset.Mba.Core
     /// <para>To prevent shutting down or logging off, set <see cref="CancellableHResultEventArgs.Cancel"/> to
     /// true; otherwise, set it to false.</para>
     /// <para>By default setup will prevent shutting down or logging off between
-    /// <see cref="BootstrapperApplication.ApplyBegin"/> and <see cref="BootstrapperApplication.ApplyComplete"/>.</para>
+    /// <see cref="IDefaultBootstrapperApplication.ApplyBegin"/> and <see cref="IDefaultBootstrapperApplication.ApplyComplete"/>.</para>
     /// <para>If <see cref="SystemShutdownEventArgs.Reasons"/> contains <see cref="EndSessionReasons.Critical"/>
     /// the bootstrapper cannot prevent the shutdown and only has a few seconds to save state or perform any other
     /// critical operations before being closed by the operating system.</para>
@@ -1950,6 +1950,10 @@ namespace WixToolset.Mba.Core
     [Serializable]
     public class LaunchApprovedExeBeginEventArgs : CancellableHResultEventArgs
     {
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="cancelRecommendation"></param>
         public LaunchApprovedExeBeginEventArgs(bool cancelRecommendation)
             : base(cancelRecommendation)
         {
@@ -1964,6 +1968,11 @@ namespace WixToolset.Mba.Core
     {
         private int processId;
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="hrStatus"></param>
+        /// <param name="processId"></param>
         public LaunchApprovedExeCompleteEventArgs(int hrStatus, int processId)
             : base(hrStatus)
         {
@@ -1988,6 +1997,11 @@ namespace WixToolset.Mba.Core
     {
         private string transactionId;
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="transactionId"></param>
+        /// <param name="cancelRecommendation"></param>
         public BeginMsiTransactionBeginEventArgs(string transactionId, bool cancelRecommendation)
             : base(cancelRecommendation)
         {
@@ -2011,6 +2025,11 @@ namespace WixToolset.Mba.Core
     {
         private string transactionId;
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="transactionId"></param>
+        /// <param name="hrStatus"></param>
         public BeginMsiTransactionCompleteEventArgs(string transactionId, int hrStatus)
             : base(hrStatus)
         {
@@ -2034,6 +2053,11 @@ namespace WixToolset.Mba.Core
     {
         private string transactionId;
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="transactionId"></param>
+        /// <param name="cancelRecommendation"></param>
         public CommitMsiTransactionBeginEventArgs(string transactionId, bool cancelRecommendation)
             : base(cancelRecommendation)
         {
@@ -2057,6 +2081,11 @@ namespace WixToolset.Mba.Core
     {
         private string transactionId;
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="transactionId"></param>
+        /// <param name="hrStatus"></param>
         public CommitMsiTransactionCompleteEventArgs(string transactionId, int hrStatus)
             : base(hrStatus)
         {
@@ -2080,6 +2109,10 @@ namespace WixToolset.Mba.Core
     {
         private string transactionId;
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="transactionId"></param>
         public RollbackMsiTransactionBeginEventArgs(string transactionId)
         {
             this.transactionId = transactionId;
@@ -2102,6 +2135,11 @@ namespace WixToolset.Mba.Core
     {
         private string transactionId;
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="transactionId"></param>
+        /// <param name="hrStatus"></param>
         public RollbackMsiTransactionCompleteEventArgs(string transactionId, int hrStatus)
             : base(hrStatus)
         {
@@ -2123,6 +2161,9 @@ namespace WixToolset.Mba.Core
     [Serializable]
     public class PauseAutomaticUpdatesBeginEventArgs : HResultEventArgs
     {
+        /// <summary>
+        /// 
+        /// </summary>
         public PauseAutomaticUpdatesBeginEventArgs()
         {
         }
@@ -2134,6 +2175,10 @@ namespace WixToolset.Mba.Core
     [Serializable]
     public class PauseAutomaticUpdatesCompleteEventArgs : StatusEventArgs
     {
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="hrStatus"></param>
         public PauseAutomaticUpdatesCompleteEventArgs(int hrStatus)
             : base(hrStatus)
         {
@@ -2146,6 +2191,9 @@ namespace WixToolset.Mba.Core
     [Serializable]
     public class SystemRestorePointBeginEventArgs : HResultEventArgs
     {
+        /// <summary>
+        /// 
+        /// </summary>
         public SystemRestorePointBeginEventArgs()
         {
         }
@@ -2157,6 +2205,10 @@ namespace WixToolset.Mba.Core
     [Serializable]
     public class SystemRestorePointCompleteEventArgs : StatusEventArgs
     {
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="hrStatus"></param>
         public SystemRestorePointCompleteEventArgs(int hrStatus)
             : base(hrStatus)
         {
diff --git a/src/WixToolset.Mba.Core/IBootstrapperApplication.cs b/src/WixToolset.Mba.Core/IBootstrapperApplication.cs
index f1a631a3..3c62370a 100644
--- a/src/WixToolset.Mba.Core/IBootstrapperApplication.cs
+++ b/src/WixToolset.Mba.Core/IBootstrapperApplication.cs
@@ -14,14 +14,26 @@ namespace WixToolset.Mba.Core
     [Guid("53C31D56-49C0-426B-AB06-099D717C67FE")]
     public interface IBootstrapperApplication
     {
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.Startup"/>.
+        /// </summary>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnStartup();
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.Shutdown"/>.
+        /// </summary>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnShutdown(ref BOOTSTRAPPER_SHUTDOWN_ACTION action);
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.SystemShutdown"/>.
+        /// </summary>
+        /// <param name="dwEndSession"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnSystemShutdown(
@@ -29,6 +41,13 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.DetectBegin"/>.
+        /// </summary>
+        /// <param name="fInstalled"></param>
+        /// <param name="cPackages"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnDetectBegin(
@@ -37,6 +56,17 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.DetectForwardCompatibleBundle"/>.
+        /// </summary>
+        /// <param name="wzBundleId"></param>
+        /// <param name="relationType"></param>
+        /// <param name="wzBundleTag"></param>
+        /// <param name="fPerMachine"></param>
+        /// <param name="wzVersion"></param>
+        /// <param name="fCancel"></param>
+        /// <param name="fIgnoreBundle"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnDetectForwardCompatibleBundle(
@@ -49,6 +79,13 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fIgnoreBundle
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.DetectUpdateBegin"/>.
+        /// </summary>
+        /// <param name="wzUpdateLocation"></param>
+        /// <param name="fCancel"></param>
+        /// <param name="fSkip"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnDetectUpdateBegin(
@@ -57,6 +94,19 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fSkip
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.DetectUpdate"/>.
+        /// </summary>
+        /// <param name="wzUpdateLocation"></param>
+        /// <param name="dw64Size"></param>
+        /// <param name="wzVersion"></param>
+        /// <param name="wzTitle"></param>
+        /// <param name="wzSummary"></param>
+        /// <param name="wzContentType"></param>
+        /// <param name="wzContent"></param>
+        /// <param name="fCancel"></param>
+        /// <param name="fStopProcessingUpdates"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnDetectUpdate(
@@ -71,6 +121,12 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fStopProcessingUpdates
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.DetectUpdateComplete"/>.
+        /// </summary>
+        /// <param name="hrStatus"></param>
+        /// <param name="fIgnoreError"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnDetectUpdateComplete(
@@ -78,6 +134,17 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fIgnoreError
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.DetectRelatedBundle"/>.
+        /// </summary>
+        /// <param name="wzBundleId"></param>
+        /// <param name="relationType"></param>
+        /// <param name="wzBundleTag"></param>
+        /// <param name="fPerMachine"></param>
+        /// <param name="wzVersion"></param>
+        /// <param name="operation"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnDetectRelatedBundle(
@@ -90,6 +157,12 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.DetectPackageBegin"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnDetectPackageBegin(
@@ -97,6 +170,14 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.DetectCompatibleMsiPackage"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="wzCompatiblePackageId"></param>
+        /// <param name="wzCompatiblePackageVersion"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnDetectCompatibleMsiPackage(
@@ -106,6 +187,17 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.DetectRelatedMsiPackage"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="wzUpgradeCode"></param>
+        /// <param name="wzProductCode"></param>
+        /// <param name="fPerMachine"></param>
+        /// <param name="wzVersion"></param>
+        /// <param name="operation"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnDetectRelatedMsiPackage(
@@ -118,6 +210,14 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.DetectTargetMsiPackage"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="wzProductCode"></param>
+        /// <param name="patchState"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnDetectTargetMsiPackage(
@@ -127,6 +227,14 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.DetectMsiFeature"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="wzFeatureId"></param>
+        /// <param name="state"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnDetectMsiFeature(
@@ -136,6 +244,13 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.DetectPackageComplete"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="hrStatus"></param>
+        /// <param name="state"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnDetectPackageComplete(
@@ -144,12 +259,23 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.U4)] PackageState state
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.DetectComplete"/>.
+        /// </summary>
+        /// <param name="hrStatus"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnDetectComplete(
             int hrStatus
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.PlanBegin"/>.
+        /// </summary>
+        /// <param name="cPackages"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnPlanBegin(
@@ -157,6 +283,14 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.PlanRelatedBundle"/>.
+        /// </summary>
+        /// <param name="wzBundleId"></param>
+        /// <param name="recommendedState"></param>
+        /// <param name="pRequestedState"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnPlanRelatedBundle(
@@ -166,6 +300,14 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.PlanPackageBegin"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="recommendedState"></param>
+        /// <param name="pRequestedState"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnPlanPackageBegin(
@@ -175,6 +317,16 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.PlanCompatibleMsiPackageBegin"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="wzCompatiblePackageId"></param>
+        /// <param name="wzCompatiblePackageVersion"></param>
+        /// <param name="recommendedState"></param>
+        /// <param name="pRequestedState"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnPlanCompatibleMsiPackageBegin(
@@ -186,6 +338,17 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.PlanCompatibleMsiPackageComplete"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="wzCompatiblePackageId"></param>
+        /// <param name="hrStatus"></param>
+        /// <param name="state"></param>
+        /// <param name="requested"></param>
+        /// <param name="execute"></param>
+        /// <param name="rollback"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnPlanCompatibleMsiPackageComplete(
@@ -198,6 +361,15 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.U4)] ActionState rollback
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.PlanTargetMsiPackage"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="wzProductCode"></param>
+        /// <param name="recommendedState"></param>
+        /// <param name="pRequestedState"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnPlanTargetMsiPackage(
@@ -208,6 +380,15 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.PlanMsiFeature"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="wzFeatureId"></param>
+        /// <param name="recommendedState"></param>
+        /// <param name="pRequestedState"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnPlanMsiFeature(
@@ -218,6 +399,17 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.PlanMsiPackage"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="fExecute"></param>
+        /// <param name="action"></param>
+        /// <param name="fCancel"></param>
+        /// <param name="actionMsiProperty"></param>
+        /// <param name="uiLevel"></param>
+        /// <param name="fDisableExternalUiHandler"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnPlanMsiPackage(
@@ -230,6 +422,16 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fDisableExternalUiHandler
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.PlanPackageComplete"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="hrStatus"></param>
+        /// <param name="state"></param>
+        /// <param name="requested"></param>
+        /// <param name="execute"></param>
+        /// <param name="rollback"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnPlanPackageComplete(
@@ -241,12 +443,23 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.U4)] ActionState rollback
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.PlanComplete"/>.
+        /// </summary>
+        /// <param name="hrStatus"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnPlanComplete(
             int hrStatus
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.ApplyBegin"/>.
+        /// </summary>
+        /// <param name="dwPhaseCount"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnApplyBegin(
@@ -254,18 +467,35 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.ElevateBegin"/>.
+        /// </summary>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnElevateBegin(
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.ElevateComplete"/>.
+        /// </summary>
+        /// <param name="hrStatus"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnElevateComplete(
             int hrStatus
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.Progress"/>.
+        /// </summary>
+        /// <param name="dwProgressPercentage"></param>
+        /// <param name="dwOverallPercentage"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnProgress(
@@ -274,6 +504,19 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.Error"/>.
+        /// </summary>
+        /// <param name="errorType"></param>
+        /// <param name="wzPackageId"></param>
+        /// <param name="dwCode"></param>
+        /// <param name="wzError"></param>
+        /// <param name="dwUIHint"></param>
+        /// <param name="cData"></param>
+        /// <param name="rgwzData"></param>
+        /// <param name="nRecommendation"></param>
+        /// <param name="pResult"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnError(
@@ -288,24 +531,47 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.I4)] ref Result pResult
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.RegisterBegin"/>.
+        /// </summary>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnRegisterBegin(
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.RegisterComplete"/>.
+        /// </summary>
+        /// <param name="hrStatus"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnRegisterComplete(
             int hrStatus
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.CacheBegin"/>.
+        /// </summary>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnCacheBegin(
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.CachePackageBegin"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="cCachePayloads"></param>
+        /// <param name="dw64PackageCacheSize"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnCachePackageBegin(
@@ -315,6 +581,15 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.CacheAcquireBegin"/>.
+        /// </summary>
+        /// <param name="wzPackageOrContainerId"></param>
+        /// <param name="wzPayloadId"></param>
+        /// <param name="operation"></param>
+        /// <param name="wzSource"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnCacheAcquireBegin(
@@ -325,6 +600,16 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.CacheAcquireProgress"/>.
+        /// </summary>
+        /// <param name="wzPackageOrContainerId"></param>
+        /// <param name="wzPayloadId"></param>
+        /// <param name="dw64Progress"></param>
+        /// <param name="dw64Total"></param>
+        /// <param name="dwOverallPercentage"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnCacheAcquireProgress(
@@ -336,6 +621,17 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.ResolveSource"/>.
+        /// </summary>
+        /// <param name="wzPackageOrContainerId"></param>
+        /// <param name="wzPayloadId"></param>
+        /// <param name="wzLocalSource"></param>
+        /// <param name="wzDownloadSource"></param>
+        /// <param name="recommendation"></param>
+        /// <param name="action"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnResolveSource(
@@ -348,6 +644,15 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.CacheAcquireComplete"/>.
+        /// </summary>
+        /// <param name="wzPackageOrContainerId"></param>
+        /// <param name="wzPayloadId"></param>
+        /// <param name="hrStatus"></param>
+        /// <param name="recommendation"></param>
+        /// <param name="pAction"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnCacheAcquireComplete(
@@ -358,6 +663,13 @@ namespace WixToolset.Mba.Core
             ref BOOTSTRAPPER_CACHEACQUIRECOMPLETE_ACTION pAction
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.CacheVerifyBegin"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="wzPayloadId"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnCacheVerifyBegin(
@@ -366,6 +678,15 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.CacheVerifyComplete"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="wzPayloadId"></param>
+        /// <param name="hrStatus"></param>
+        /// <param name="recommendation"></param>
+        /// <param name="action"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnCacheVerifyComplete(
@@ -376,6 +697,14 @@ namespace WixToolset.Mba.Core
             ref BOOTSTRAPPER_CACHEVERIFYCOMPLETE_ACTION action
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.CachePackageComplete"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="hrStatus"></param>
+        /// <param name="recommendation"></param>
+        /// <param name="action"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnCachePackageComplete(
@@ -385,12 +714,23 @@ namespace WixToolset.Mba.Core
             ref BOOTSTRAPPER_CACHEPACKAGECOMPLETE_ACTION action
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.CacheComplete"/>.
+        /// </summary>
+        /// <param name="hrStatus"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnCacheComplete(
             int hrStatus
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.ExecuteBegin"/>.
+        /// </summary>
+        /// <param name="cExecutingPackages"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnExecuteBegin(
@@ -398,6 +738,16 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.ExecutePackageBegin"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="fExecute"></param>
+        /// <param name="action"></param>
+        /// <param name="uiLevel"></param>
+        /// <param name="fDisableExternalUiHandler"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnExecutePackageBegin(
@@ -409,6 +759,13 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.ExecutePatchTarget"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="wzTargetProductCode"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnExecutePatchTarget(
@@ -417,6 +774,14 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.ExecuteProgress"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="dwProgressPercentage"></param>
+        /// <param name="dwOverallPercentage"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnExecuteProgress(
@@ -426,6 +791,18 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.ExecuteMsiMessage"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="messageType"></param>
+        /// <param name="dwUIHint"></param>
+        /// <param name="wzMessage"></param>
+        /// <param name="cData"></param>
+        /// <param name="rgwzData"></param>
+        /// <param name="nRecommendation"></param>
+        /// <param name="pResult"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnExecuteMsiMessage(
@@ -439,6 +816,15 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.I4)] ref Result pResult
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.ExecuteFilesInUse"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="cFiles"></param>
+        /// <param name="rgwzFiles"></param>
+        /// <param name="nRecommendation"></param>
+        /// <param name="pResult"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnExecuteFilesInUse(
@@ -449,6 +835,15 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.I4)] ref Result pResult
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.ExecutePackageComplete"/>.
+        /// </summary>
+        /// <param name="wzPackageId"></param>
+        /// <param name="hrStatus"></param>
+        /// <param name="restart"></param>
+        /// <param name="recommendation"></param>
+        /// <param name="pAction"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnExecutePackageComplete(
@@ -459,24 +854,47 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.I4)] ref BOOTSTRAPPER_EXECUTEPACKAGECOMPLETE_ACTION pAction
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.ExecuteComplete"/>.
+        /// </summary>
+        /// <param name="hrStatus"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnExecuteComplete(
             int hrStatus
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.UnregisterBegin"/>.
+        /// </summary>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnUnregisterBegin(
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.UnregisterComplete"/>.
+        /// </summary>
+        /// <param name="hrStatus"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnUnregisterComplete(
             int hrStatus
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.ApplyComplete"/>.
+        /// </summary>
+        /// <param name="hrStatus"></param>
+        /// <param name="restart"></param>
+        /// <param name="recommendation"></param>
+        /// <param name="pAction"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnApplyComplete(
@@ -486,12 +904,23 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.I4)] ref BOOTSTRAPPER_APPLYCOMPLETE_ACTION pAction
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.LaunchApprovedExeBegin"/>.
+        /// </summary>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnLaunchApprovedExeBegin(
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.LaunchApprovedExeComplete"/>.
+        /// </summary>
+        /// <param name="hrStatus"></param>
+        /// <param name="processId"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnLaunchApprovedExeComplete(
@@ -499,6 +928,12 @@ namespace WixToolset.Mba.Core
             int processId
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.BeginMsiTransactionBegin"/>.
+        /// </summary>
+        /// <param name="wzTransactionId"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnBeginMsiTransactionBegin(
@@ -506,6 +941,12 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.BeginMsiTransactionComplete"/>.
+        /// </summary>
+        /// <param name="wzTransactionId"></param>
+        /// <param name="hrStatus"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnBeginMsiTransactionComplete(
@@ -513,6 +954,12 @@ namespace WixToolset.Mba.Core
             int hrStatus
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.CommitMsiTransactionBegin"/>.
+        /// </summary>
+        /// <param name="wzTransactionId"></param>
+        /// <param name="fCancel"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnCommitMsiTransactionBegin(
@@ -520,6 +967,12 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.CommitMsiTransactionComplete"/>.
+        /// </summary>
+        /// <param name="wzTransactionId"></param>
+        /// <param name="hrStatus"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnCommitMsiTransactionComplete(
@@ -527,12 +980,23 @@ namespace WixToolset.Mba.Core
             int hrStatus
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.RollbackMsiTransactionBegin"/>.
+        /// </summary>
+        /// <param name="wzTransactionId"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnRollbackMsiTransactionBegin(
             [MarshalAs(UnmanagedType.LPWStr)] string wzTransactionId
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.RollbackMsiTransactionComplete"/>.
+        /// </summary>
+        /// <param name="wzTransactionId"></param>
+        /// <param name="hrStatus"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnRollbackMsiTransactionComplete(
@@ -540,28 +1004,54 @@ namespace WixToolset.Mba.Core
             int hrStatus
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.PauseAutomaticUpdatesBegin"/>.
+        /// </summary>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnPauseAutomaticUpdatesBegin(
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.PauseAutomaticUpdatesComplete"/>.
+        /// </summary>
+        /// <param name="hrStatus"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnPauseAutomaticUpdatesComplete(
             int hrStatus
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.SystemRestorePointBegin"/>.
+        /// </summary>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnSystemRestorePointBegin(
             );
 
+        /// <summary>
+        /// See <see cref="IDefaultBootstrapperApplication.SystemRestorePointComplete"/>.
+        /// </summary>
+        /// <param name="hrStatus"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int OnSystemRestorePointComplete(
             int hrStatus
             );
 
+        /// <summary>
+        /// Low level method that is called directly from the engine.
+        /// </summary>
+        /// <param name="message"></param>
+        /// <param name="pvArgs"></param>
+        /// <param name="pvResults"></param>
+        /// <param name="pvContext"></param>
+        /// <returns></returns>
         [PreserveSig]
         [return: MarshalAs(UnmanagedType.I4)]
         int BAProc(
@@ -571,6 +1061,14 @@ namespace WixToolset.Mba.Core
             IntPtr pvContext
             );
 
+        /// <summary>
+        /// Low level method that is called directly from the engine.
+        /// </summary>
+        /// <param name="message"></param>
+        /// <param name="pvArgs"></param>
+        /// <param name="pvResults"></param>
+        /// <param name="phr"></param>
+        /// <param name="pvContext"></param>
         void BAProcFallback(
             int message,
             IntPtr pvArgs,
@@ -585,34 +1083,131 @@ namespace WixToolset.Mba.Core
     /// </summary>
     public enum Display
     {
+        /// <summary>
+        /// 
+        /// </summary>
         Unknown,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Embedded,
+
+        /// <summary>
+        /// 
+        /// </summary>
         None,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Passive,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Full,
     }
 
     /// <summary>
-    /// Messages from Windows Installer.
+    /// Messages from Windows Installer (msi.h).
     /// </summary>
     public enum InstallMessage
     {
+        /// <summary>
+        /// premature termination, possibly fatal OOM
+        /// </summary>
         FatalExit,
+
+        /// <summary>
+        /// formatted error message
+        /// </summary>
         Error = 0x01000000,
+
+        /// <summary>
+        /// formatted warning message
+        /// </summary>
         Warning = 0x02000000,
+
+        /// <summary>
+        /// user request message
+        /// </summary>
         User = 0x03000000,
+
+        /// <summary>
+        /// informative message for log
+        /// </summary>
         Info = 0x04000000,
+
+        /// <summary>
+        /// list of files in use that need to be replaced
+        /// </summary>
         FilesInUse = 0x05000000,
+
+        /// <summary>
+        /// request to determine a valid source location
+        /// </summary>
         ResolveSource = 0x06000000,
+
+        /// <summary>
+        /// insufficient disk space message
+        /// </summary>
         OutOfDiskSpace = 0x07000000,
+
+        /// <summary>
+        /// start of action: action name &amp; description
+        /// </summary>
         ActionStart = 0x08000000,
+
+        /// <summary>
+        /// formatted data associated with individual action item
+        /// </summary>
         ActionData = 0x09000000,
+
+        /// <summary>
+        /// progress gauge info: units so far, total
+        /// </summary>
         Progress = 0x0a000000,
+
+        /// <summary>
+        /// product info for dialog: language Id, dialog caption
+        /// </summary>
         CommonData = 0x0b000000,
+
+        /// <summary>
+        /// sent prior to UI initialization, no string data
+        /// </summary>
         Initialize = 0x0c000000,
+
+        /// <summary>
+        /// sent after UI termination, no string data
+        /// </summary>
         Terminate = 0x0d000000,
+
+        /// <summary>
+        /// sent prior to display or authored dialog or wizard
+        /// </summary>
         ShowDialog = 0x0e000000,
+
+        /// <summary>
+        /// log only, to log performance number like action time
+        /// </summary>
+        Performance = 0x0f000000,
+
+        /// <summary>
+        /// the list of apps that the user can request Restart Manager to shut down and restart
+        /// </summary>
         RMFilesInUse = 0x19000000,
+
+        /// <summary>
+        /// sent prior to server-side install of a product
+        /// </summary>
+        InstallStart = 0x1a000000,
+
+        /// <summary>
+        /// sent after server-side install
+        /// </summary>
+        InstallEnd = 0x1B000000,
     }
 
     /// <summary>
@@ -620,30 +1215,100 @@ namespace WixToolset.Mba.Core
     /// </summary>
     public enum Restart
     {
+        /// <summary>
+        /// 
+        /// </summary>
         Unknown,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Never,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Prompt,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Automatic,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Always,
     }
 
     /// <summary>
-    /// Result codes.
+    /// Result codes (based on Dialog Box Command IDs from WinUser.h).
     /// </summary>
     public enum Result
     {
+        /// <summary>
+        /// 
+        /// </summary>
         Error = -1,
+
+        /// <summary>
+        /// 
+        /// </summary>
         None,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Ok,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Cancel,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Abort,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Retry,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Ignore,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Yes,
+
+        /// <summary>
+        /// 
+        /// </summary>
         No,
+
+        /// <summary>
+        /// /
+        /// </summary>
         Close,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Help,
+
+        /// <summary>
+        /// 
+        /// </summary>
         TryAgain,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Continue,
     }
 
@@ -652,6 +1317,9 @@ namespace WixToolset.Mba.Core
     /// </summary>
     public enum ResumeType
     {
+        /// <summary>
+        /// 
+        /// </summary>
         None,
 
         /// <summary>
@@ -721,8 +1389,14 @@ namespace WixToolset.Mba.Core
         Apply,
     };
 
+    /// <summary>
+    /// The calculated operation for the related bundle.
+    /// </summary>
     public enum RelatedOperation
     {
+        /// <summary>
+        /// 
+        /// </summary>
         None,
 
         /// <summary>
@@ -803,12 +1477,39 @@ namespace WixToolset.Mba.Core
     /// </summary>
     public enum RelationType
     {
+        /// <summary>
+        /// 
+        /// </summary>
         None,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Detect,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Upgrade,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Addon,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Patch,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Dependent,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Update,
     }
 
@@ -840,72 +1541,161 @@ namespace WixToolset.Mba.Core
     }
 
     /// <summary>
-    /// The available actions for OnApplyComplete.
+    /// The available actions for <see cref="IDefaultBootstrapperApplication.ApplyComplete"/>.
     /// </summary>
     public enum BOOTSTRAPPER_APPLYCOMPLETE_ACTION
     {
+        /// <summary>
+        /// 
+        /// </summary>
         None,
+
+        /// <summary>
+        /// Instructs the engine to restart.
+        /// The engine will not launch again after the machine is rebooted.
+        /// Ignored if reboot was already initiated by <see cref="IDefaultBootstrapperApplication.ExecutePackageComplete"/>.
+        /// </summary>
         Restart,
     }
 
     /// <summary>
-    /// The available actions for OnCacheAcquireComplete.
+    /// The available actions for <see cref="IDefaultBootstrapperApplication.CacheAcquireComplete"/>.
     /// </summary>
     public enum BOOTSTRAPPER_CACHEACQUIRECOMPLETE_ACTION
     {
+        /// <summary>
+        /// 
+        /// </summary>
         None,
+
+        /// <summary>
+        /// Instructs the engine to try the acquisition of the package again.
+        /// Ignored if hrStatus is a success.
+        /// </summary>
         Retry,
     }
 
     /// <summary>
-    /// The available actions for OnCachePackageComplete.
+    /// The available actions for <see cref="IDefaultBootstrapperApplication.CachePackageComplete"/>.
     /// </summary>
     public enum BOOTSTRAPPER_CACHEPACKAGECOMPLETE_ACTION
     {
+        /// <summary>
+        /// 
+        /// </summary>
         None,
+
+        /// <summary>
+        /// Instructs the engine to ignore non-vital package failures and continue with the caching.
+        /// Ignored if hrStatus is a success or the package is vital.
+        /// </summary>
         Ignore,
+
+        /// <summary>
+        /// Instructs the engine to try the acquisition and verification of the package again.
+        /// Ignored if hrStatus is a success.
+        /// </summary>
         Retry,
     }
 
     /// <summary>
-    /// The available actions for OnCacheVerifyComplete.
+    /// The available actions for <see cref="IDefaultBootstrapperApplication.CacheVerifyComplete"/>.
     /// </summary>
     public enum BOOTSTRAPPER_CACHEVERIFYCOMPLETE_ACTION
     {
+        /// <summary>
+        /// 
+        /// </summary>
         None,
+
+        /// <summary>
+        /// Ignored if hrStatus is a success.
+        /// </summary>
         RetryVerification,
+
+        /// <summary>
+        /// Ignored if hrStatus is a success.
+        /// </summary>
         RetryAcquisition,
     }
 
     /// <summary>
-    /// The available actions for OnExecutePackageComplete.
+    /// The available actions for <see cref="IDefaultBootstrapperApplication.ExecutePackageComplete"/>.
     /// </summary>
     public enum BOOTSTRAPPER_EXECUTEPACKAGECOMPLETE_ACTION
     {
+        /// <summary>
+        /// 
+        /// </summary>
         None,
+
+        /// <summary>
+        /// Instructs the engine to ignore non-vital package failures and continue with the install.
+        /// Ignored if hrStatus is a success or the package is vital.
+        /// </summary>
         Ignore,
+
+        /// <summary>
+        /// Instructs the engine to try the execution of the package again.
+        /// Ignored if hrStatus is a success.
+        /// </summary>
         Retry,
+
+        /// <summary>
+        /// Instructs the engine to stop processing the chain and restart.
+        /// The engine will launch again after the machine is restarted.
+        /// </summary>
         Restart,
+
+        /// <summary>
+        /// Instructs the engine to stop processing the chain and suspend the current state.
+        /// </summary>
         Suspend,
     }
 
     /// <summary>
-    /// The available actions for OnResolveSource.
+    /// The available actions for <see cref="IDefaultBootstrapperApplication.ResolveSource"/>.
     /// </summary>
     public enum BOOTSTRAPPER_RESOLVESOURCE_ACTION
     {
+        /// <summary>
+        /// Instructs the engine that the source can't be found.
+        /// </summary>
         None,
+
+        /// <summary>
+        /// Instructs the engine to try the local source again.
+        /// </summary>
         Retry,
+
+        /// <summary>
+        /// Instructs the engine to try the download source.
+        /// </summary>
         Download,
     }
 
     /// <summary>
-    /// The available actions for OnShutdown.
+    /// The available actions for <see cref="IDefaultBootstrapperApplication.Shutdown"/>.
     /// </summary>
     public enum BOOTSTRAPPER_SHUTDOWN_ACTION
     {
+        /// <summary>
+        /// 
+        /// </summary>
         None,
+
+        /// <summary>
+        /// Instructs the engine to restart.
+        /// The engine will not launch again after the machine is rebooted.
+        /// Ignored if reboot was already initiated by <see cref="IDefaultBootstrapperApplication.ExecutePackageComplete"/>.
+        /// </summary>
         Restart,
+
+        /// <summary>
+        /// Instructs the engine to unload the bootstrapper application and
+        /// restart the engine which will load the bootstrapper application again.
+        /// Typically used to switch from a native bootstrapper application to a managed one.
+        /// </summary>
         ReloadBootstrapper,
     }
 
diff --git a/src/WixToolset.Mba.Core/IBootstrapperApplicationData.cs b/src/WixToolset.Mba.Core/IBootstrapperApplicationData.cs
index a19a34b5..23a1c8a3 100644
--- a/src/WixToolset.Mba.Core/IBootstrapperApplicationData.cs
+++ b/src/WixToolset.Mba.Core/IBootstrapperApplicationData.cs
@@ -4,9 +4,19 @@ namespace WixToolset.Mba.Core
 {
     using System.IO;
 
+    /// <summary>
+    /// Interface for BootstrapperApplicationData.xml.
+    /// </summary>
     public interface IBootstrapperApplicationData
     {
+        /// <summary>
+        /// The BootstrapperApplicationData.xml file.
+        /// </summary>
         FileInfo BADataFile { get; }
+
+        /// <summary>
+        /// The BA manifest.
+        /// </summary>
         IBundleInfo Bundle { get; }
     }
 }
\ No newline at end of file
diff --git a/src/WixToolset.Mba.Core/IBootstrapperApplicationFactory.cs b/src/WixToolset.Mba.Core/IBootstrapperApplicationFactory.cs
index b9c62a99..0f9193d0 100644
--- a/src/WixToolset.Mba.Core/IBootstrapperApplicationFactory.cs
+++ b/src/WixToolset.Mba.Core/IBootstrapperApplicationFactory.cs
@@ -6,12 +6,20 @@ namespace WixToolset.Mba.Core
     using System.CodeDom.Compiler;
     using System.Runtime.InteropServices;
 
+    /// <summary>
+    /// Interface used by WixToolset.Mba.Host to dynamically load the BA.
+    /// </summary>
     [ComVisible(true)]
     [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
     [Guid("2965A12F-AC7B-43A0-85DF-E4B2168478A4")]
     [GeneratedCodeAttribute("WixToolset.Bootstrapper.InteropCodeGenerator", "1.0.0.0")]
     public interface IBootstrapperApplicationFactory
     {
+        /// <summary>
+        /// Low level method called by the native host.
+        /// </summary>
+        /// <param name="pArgs"></param>
+        /// <param name="pResults"></param>
         void Create(
             IntPtr pArgs,
             IntPtr pResults
@@ -21,7 +29,7 @@ namespace WixToolset.Mba.Core
     [Serializable]
     [StructLayout(LayoutKind.Sequential)]
     [GeneratedCodeAttribute("WixToolset.Bootstrapper.InteropCodeGenerator", "1.0.0.0")]
-    public struct Command
+    internal struct Command
     {
         // Strings must be declared as pointers so that Marshaling doesn't free them.
         [MarshalAs(UnmanagedType.I4)] internal int cbSize;
@@ -55,25 +63,4 @@ namespace WixToolset.Mba.Core
                 Marshal.PtrToStringUni(this.wzBootstrapperApplicationDataPath));
         }
     }
-
-    [Serializable]
-    [StructLayout(LayoutKind.Sequential)]
-    [GeneratedCodeAttribute("WixToolset.Bootstrapper.InteropCodeGenerator", "1.0.0.0")]
-    public struct BootstrapperCreateArgs
-    {
-        [MarshalAs(UnmanagedType.I4)] public readonly int cbSize;
-        [MarshalAs(UnmanagedType.I8)] public readonly long qwEngineAPIVersion;
-        public readonly IntPtr pfnBootstrapperEngineProc;
-        public readonly IntPtr pvBootstrapperEngineProcContext;
-        public readonly IntPtr pCommand;
-
-        public BootstrapperCreateArgs(long version, IntPtr pEngineProc, IntPtr pEngineContext, IntPtr pCommand)
-        {
-            this.cbSize = Marshal.SizeOf(typeof(BootstrapperCreateArgs));
-            this.qwEngineAPIVersion = version;
-            this.pfnBootstrapperEngineProc = pEngineProc;
-            this.pvBootstrapperEngineProcContext = pEngineContext;
-            this.pCommand = pCommand;
-        }
-    }
 }
diff --git a/src/WixToolset.Mba.Core/IBootstrapperCommand.cs b/src/WixToolset.Mba.Core/IBootstrapperCommand.cs
index 889db529..e861813f 100644
--- a/src/WixToolset.Mba.Core/IBootstrapperCommand.cs
+++ b/src/WixToolset.Mba.Core/IBootstrapperCommand.cs
@@ -33,6 +33,9 @@ namespace WixToolset.Mba.Core
         /// <exception type="Win32Exception">The command line could not be parsed into an array.</exception>
         string[] CommandLineArgs { get; }
 
+        /// <summary>
+        /// Hint for the initial visibility of the window.
+        /// </summary>
         int CmdShow { get; }
 
         /// <summary>
diff --git a/src/WixToolset.Mba.Core/IBootstrapperEngine.cs b/src/WixToolset.Mba.Core/IBootstrapperEngine.cs
index 5cc42071..ddf223df 100644
--- a/src/WixToolset.Mba.Core/IBootstrapperEngine.cs
+++ b/src/WixToolset.Mba.Core/IBootstrapperEngine.cs
@@ -16,16 +16,33 @@ namespace WixToolset.Mba.Core
     [GeneratedCodeAttribute("WixToolset.Bootstrapper.InteropCodeGenerator", "1.0.0.0")]
     public interface IBootstrapperEngine
     {
+        /// <summary>
+        /// See <see cref="IEngine.PackageCount"/>.
+        /// </summary>
+        /// <param name="pcPackages"></param>
         void GetPackageCount(
             [MarshalAs(UnmanagedType.U4)] out int pcPackages
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.GetVariableNumeric(string)"/>.
+        /// </summary>
+        /// <param name="wzVariable"></param>
+        /// <param name="pllValue"></param>
+        /// <returns></returns>
         [PreserveSig]
         int GetVariableNumeric(
             [MarshalAs(UnmanagedType.LPWStr)] string wzVariable,
             out long pllValue
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.GetVariableString(string)"/>.
+        /// </summary>
+        /// <param name="wzVariable"></param>
+        /// <param name="wzValue"></param>
+        /// <param name="pcchValue"></param>
+        /// <returns></returns>
         [PreserveSig]
         int GetVariableString(
             [MarshalAs(UnmanagedType.LPWStr)] string wzVariable,
@@ -33,6 +50,13 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.U4)] ref int pcchValue
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.GetVariableVersion(string)"/>.
+        /// </summary>
+        /// <param name="wzVariable"></param>
+        /// <param name="wzValue"></param>
+        /// <param name="pcchValue"></param>
+        /// <returns></returns>
         [PreserveSig]
         int GetVariableVersion(
             [MarshalAs(UnmanagedType.LPWStr)] string wzVariable,
@@ -40,6 +64,13 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.U4)] ref int pcchValue
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.FormatString(string)"/>.
+        /// </summary>
+        /// <param name="wzIn"></param>
+        /// <param name="wzOut"></param>
+        /// <param name="pcchOut"></param>
+        /// <returns></returns>
         [PreserveSig]
         int FormatString(
             [MarshalAs(UnmanagedType.LPWStr)] string wzIn,
@@ -47,6 +78,13 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.U4)] ref int pcchOut
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.EscapeString(string)"/>.
+        /// </summary>
+        /// <param name="wzIn"></param>
+        /// <param name="wzOut"></param>
+        /// <param name="pcchOut"></param>
+        /// <returns></returns>
         [PreserveSig]
         int EscapeString(
             [MarshalAs(UnmanagedType.LPWStr)] string wzIn,
@@ -54,16 +92,33 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.U4)] ref int pcchOut
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.EvaluateCondition(string)"/>.
+        /// </summary>
+        /// <param name="wzCondition"></param>
+        /// <param name="pf"></param>
         void EvaluateCondition(
             [MarshalAs(UnmanagedType.LPWStr)] string wzCondition,
             [MarshalAs(UnmanagedType.Bool)] out bool pf
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.Log(LogLevel, string)"/>.
+        /// </summary>
+        /// <param name="level"></param>
+        /// <param name="wzMessage"></param>
         void Log(
             [MarshalAs(UnmanagedType.U4)] LogLevel level,
             [MarshalAs(UnmanagedType.LPWStr)] string wzMessage
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.SendEmbeddedError(int, string, int)"/>.
+        /// </summary>
+        /// <param name="dwErrorCode"></param>
+        /// <param name="wzMessage"></param>
+        /// <param name="dwUIHint"></param>
+        /// <param name="pnResult"></param>
         void SendEmbeddedError(
             [MarshalAs(UnmanagedType.U4)] int dwErrorCode,
             [MarshalAs(UnmanagedType.LPWStr)] string wzMessage,
@@ -71,12 +126,27 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.I4)] out int pnResult
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.SendEmbeddedProgress(int, int)"/>.
+        /// </summary>
+        /// <param name="dwProgressPercentage"></param>
+        /// <param name="dwOverallProgressPercentage"></param>
+        /// <param name="pnResult"></param>
         void SendEmbeddedProgress(
             [MarshalAs(UnmanagedType.U4)] int dwProgressPercentage,
             [MarshalAs(UnmanagedType.U4)] int dwOverallProgressPercentage,
             [MarshalAs(UnmanagedType.I4)] out int pnResult
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.SetUpdate(string, string, long, UpdateHashType, byte[])"/>.
+        /// </summary>
+        /// <param name="wzLocalSource"></param>
+        /// <param name="wzDownloadSource"></param>
+        /// <param name="qwValue"></param>
+        /// <param name="hashType"></param>
+        /// <param name="rgbHash"></param>
+        /// <param name="cbHash"></param>
         void SetUpdate(
             [MarshalAs(UnmanagedType.LPWStr)] string wzLocalSource,
             [MarshalAs(UnmanagedType.LPWStr)] string wzDownloadSource,
@@ -86,12 +156,26 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.U4)] int cbHash
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.SetLocalSource(string, string, string)"/>.
+        /// </summary>
+        /// <param name="wzPackageOrContainerId"></param>
+        /// <param name="wzPayloadId"></param>
+        /// <param name="wzPath"></param>
         void SetLocalSource(
             [MarshalAs(UnmanagedType.LPWStr)] string wzPackageOrContainerId,
             [MarshalAs(UnmanagedType.LPWStr)] string wzPayloadId,
             [MarshalAs(UnmanagedType.LPWStr)] string wzPath
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.SetDownloadSource(string, string, string, string, string)"/>.
+        /// </summary>
+        /// <param name="wzPackageOrContainerId"></param>
+        /// <param name="wzPayloadId"></param>
+        /// <param name="wzUrl"></param>
+        /// <param name="wzUser"></param>
+        /// <param name="wzPassword"></param>
         void SetDownloadSource(
             [MarshalAs(UnmanagedType.LPWStr)] string wzPackageOrContainerId,
             [MarshalAs(UnmanagedType.LPWStr)] string wzPayloadId,
@@ -100,45 +184,92 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.LPWStr)] string wzPassword
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.SetVariableNumeric(string, long)"/>.
+        /// </summary>
+        /// <param name="wzVariable"></param>
+        /// <param name="llValue"></param>
         void SetVariableNumeric(
             [MarshalAs(UnmanagedType.LPWStr)] string wzVariable,
             long llValue
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.SetVariableString(string, string, bool)"/>.
+        /// </summary>
+        /// <param name="wzVariable"></param>
+        /// <param name="wzValue"></param>
+        /// <param name="fFormatted"></param>
         void SetVariableString(
             [MarshalAs(UnmanagedType.LPWStr)] string wzVariable,
                                               IntPtr wzValue,
             [MarshalAs(UnmanagedType.Bool)]   bool fFormatted
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.SetVariableVersion(string, string)"/>.
+        /// </summary>
+        /// <param name="wzVariable"></param>
+        /// <param name="wzValue"></param>
         void SetVariableVersion(
             [MarshalAs(UnmanagedType.LPWStr)] string wzVariable,
                                               IntPtr wzValue
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.CloseSplashScreen"/>.
+        /// </summary>
         void CloseSplashScreen();
 
+        /// <summary>
+        /// See <see cref="IEngine.Detect(IntPtr)"/>.
+        /// </summary>
+        /// <param name="hwndParent"></param>
         void Detect(
             IntPtr hwndParent
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.Plan(LaunchAction)"/>.
+        /// </summary>
+        /// <param name="action"></param>
         void Plan(
             [MarshalAs(UnmanagedType.U4)] LaunchAction action
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.Elevate(IntPtr)"/>.
+        /// </summary>
+        /// <param name="hwndParent"></param>
+        /// <returns></returns>
         [PreserveSig]
         int Elevate(
             IntPtr hwndParent
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.Apply(IntPtr)"/>.
+        /// </summary>
+        /// <param name="hwndParent"></param>
         void Apply(
             IntPtr hwndParent
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.Quit(int)"/>.
+        /// </summary>
+        /// <param name="dwExitCode"></param>
         void Quit(
             [MarshalAs(UnmanagedType.U4)] int dwExitCode
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.LaunchApprovedExe(IntPtr, string, string, int)"/>.
+        /// </summary>
+        /// <param name="hwndParent"></param>
+        /// <param name="wzApprovedExeForElevationId"></param>
+        /// <param name="wzArguments"></param>
+        /// <param name="dwWaitForInputIdleTimeout"></param>
         void LaunchApprovedExe(
             IntPtr hwndParent,
             [MarshalAs(UnmanagedType.LPWStr)] string wzApprovedExeForElevationId,
@@ -146,6 +277,12 @@ namespace WixToolset.Mba.Core
             [MarshalAs(UnmanagedType.U4)] int dwWaitForInputIdleTimeout
             );
 
+        /// <summary>
+        /// See <see cref="IEngine.CompareVersions(string, string)"/>.
+        /// </summary>
+        /// <param name="wzVersion1"></param>
+        /// <param name="wzVersion2"></param>
+        /// <param name="pnResult"></param>
         void CompareVersions(
             [MarshalAs(UnmanagedType.LPWStr)] string wzVersion1,
             [MarshalAs(UnmanagedType.LPWStr)] string wzVersion2,
@@ -158,14 +295,49 @@ namespace WixToolset.Mba.Core
     /// </summary>
     public enum ActionState
     {
+        /// <summary>
+        /// 
+        /// </summary>
         None,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Uninstall,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Install,
+
+        /// <summary>
+        /// 
+        /// </summary>
         AdminInstall,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Modify,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Repair,
+
+        /// <summary>
+        /// 
+        /// </summary>
         MinorUpgrade,
+
+        /// <summary>
+        /// 
+        /// </summary>
         MajorUpgrade,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Patch,
     }
 
@@ -174,15 +346,54 @@ namespace WixToolset.Mba.Core
     /// </summary>
     public enum LaunchAction
     {
+        /// <summary>
+        /// 
+        /// </summary>
         Unknown,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Help,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Layout,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Uninstall,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Cache,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Install,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Modify,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Repair,
+
+        /// <summary>
+        /// 
+        /// </summary>
         UpdateReplace,
+
+        /// <summary>
+        /// 
+        /// </summary>
         UpdateReplaceEmbedded,
     }
 
@@ -238,11 +449,34 @@ namespace WixToolset.Mba.Core
     /// </summary>
     public enum PackageState
     {
+        /// <summary>
+        /// 
+        /// </summary>
         Unknown,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Obsolete,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Absent,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Cached,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Present,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Superseded,
     }
 
@@ -251,11 +485,34 @@ namespace WixToolset.Mba.Core
     /// </summary>
     public enum RequestState
     {
+        /// <summary>
+        /// 
+        /// </summary>
         None,
+
+        /// <summary>
+        /// /
+        /// </summary>
         ForceAbsent,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Absent,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Cache,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Present,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Repair,
     }
 
@@ -264,10 +521,29 @@ namespace WixToolset.Mba.Core
     /// </summary>
     public enum FeatureState
     {
+        /// <summary>
+        /// 
+        /// </summary>
         Unknown,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Absent,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Advertised,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Local,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Source,
     }
 
@@ -276,12 +552,39 @@ namespace WixToolset.Mba.Core
     /// </summary>
     public enum FeatureAction
     {
+        /// <summary>
+        /// 
+        /// </summary>
         None,
+
+        /// <summary>
+        /// 
+        /// </summary>
         AddLocal,
+
+        /// <summary>
+        /// 
+        /// </summary>
         AddSource,
+
+        /// <summary>
+        /// 
+        /// </summary>
         AddDefault,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Reinstall,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Advertise,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Remove,
     }
 }
diff --git a/src/WixToolset.Mba.Core/IBundleInfo.cs b/src/WixToolset.Mba.Core/IBundleInfo.cs
index d471c677..f4a82f36 100644
--- a/src/WixToolset.Mba.Core/IBundleInfo.cs
+++ b/src/WixToolset.Mba.Core/IBundleInfo.cs
@@ -4,13 +4,36 @@ namespace WixToolset.Mba.Core
 {
     using System.Collections.Generic;
 
+    /// <summary>
+    /// BA manifest data.
+    /// </summary>
     public interface IBundleInfo
     {
+        /// <summary>
+        /// 
+        /// </summary>
         string LogVariable { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         string Name { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         IDictionary<string, IPackageInfo> Packages { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         bool PerMachine { get; }
 
+        /// <summary>
+        /// Adds a related bundle as a package.
+        /// </summary>
+        /// <param name="e"></param>
+        /// <returns>The created <see cref="IPackageInfo"/>.</returns>
         IPackageInfo AddRelatedBundleAsPackage(DetectRelatedBundleEventArgs e);
     }
 }
\ No newline at end of file
diff --git a/src/WixToolset.Mba.Core/IDefaultBootstrapperApplication.cs b/src/WixToolset.Mba.Core/IDefaultBootstrapperApplication.cs
index 4a30da7e..b7e4759c 100644
--- a/src/WixToolset.Mba.Core/IDefaultBootstrapperApplication.cs
+++ b/src/WixToolset.Mba.Core/IDefaultBootstrapperApplication.cs
@@ -4,73 +4,351 @@ namespace WixToolset.Mba.Core
 {
     using System;
 
+    /// <summary>
+    /// Interface for built-in implementation of <see cref="IBootstrapperApplication"/>.
+    /// </summary>
     public interface IDefaultBootstrapperApplication : IBootstrapperApplication
     {
+        /// <summary>
+        /// Fired when the engine has begun installing the bundle.
+        /// </summary>
         event EventHandler<ApplyBeginEventArgs> ApplyBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed installing the bundle.
+        /// </summary>
         event EventHandler<ApplyCompleteEventArgs> ApplyComplete;
+
+        /// <summary>
+        /// Fired when the engine is about to begin an MSI transaction.
+        /// </summary>
         event EventHandler<BeginMsiTransactionBeginEventArgs> BeginMsiTransactionBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed beginning an MSI transaction.
+        /// </summary>
         event EventHandler<BeginMsiTransactionCompleteEventArgs> BeginMsiTransactionComplete;
+
+        /// <summary>
+        /// Fired when the engine has begun acquiring the installation sources.
+        /// </summary>
         event EventHandler<CacheAcquireBeginEventArgs> CacheAcquireBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed the acquisition of the installation sources.
+        /// </summary>
         event EventHandler<CacheAcquireCompleteEventArgs> CacheAcquireComplete;
+
+        /// <summary>
+        /// Fired when the engine has progress acquiring the installation sources.
+        /// </summary>
         event EventHandler<CacheAcquireProgressEventArgs> CacheAcquireProgress;
+
+        /// <summary>
+        /// Fired when the engine has begun caching the installation sources.
+        /// </summary>
         event EventHandler<CacheBeginEventArgs> CacheBegin;
+
+        /// <summary>
+        /// Fired after the engine has cached the installation sources.
+        /// </summary>
         event EventHandler<CacheCompleteEventArgs> CacheComplete;
+
+        /// <summary>
+        /// Fired when the engine has begun caching a specific package.
+        /// </summary>
         event EventHandler<CachePackageBeginEventArgs> CachePackageBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed caching a specific package.
+        /// </summary>
         event EventHandler<CachePackageCompleteEventArgs> CachePackageComplete;
+
+        /// <summary>
+        /// Fired when the engine begins the verification of the acquired installation sources.
+        /// </summary>
         event EventHandler<CacheVerifyBeginEventArgs> CacheVerifyBegin;
+
+        /// <summary>
+        /// Fired when the engine complete the verification of the acquired installation sources.
+        /// </summary>
         event EventHandler<CacheVerifyCompleteEventArgs> CacheVerifyComplete;
+
+        /// <summary>
+        /// Fired when the engine is about to commit an MSI transaction.
+        /// </summary>
         event EventHandler<CommitMsiTransactionBeginEventArgs> CommitMsiTransactionBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed comitting an MSI transaction.
+        /// </summary>
         event EventHandler<CommitMsiTransactionCompleteEventArgs> CommitMsiTransactionComplete;
+
+        /// <summary>
+        /// Fired when the overall detection phase has begun.
+        /// </summary>
         event EventHandler<DetectBeginEventArgs> DetectBegin;
+
+        /// <summary>
+        /// Fired when a package was not detected but a package using the same provider key was.
+        /// </summary>
         event EventHandler<DetectCompatibleMsiPackageEventArgs> DetectCompatibleMsiPackage;
+
+        /// <summary>
+        /// Fired when the detection phase has completed.
+        /// </summary>
         event EventHandler<DetectCompleteEventArgs> DetectComplete;
+
+        /// <summary>
+        /// Fired when a forward compatible bundle is detected.
+        /// </summary>
         event EventHandler<DetectForwardCompatibleBundleEventArgs> DetectForwardCompatibleBundle;
+
+        /// <summary>
+        /// Fired when a feature in an MSI package has been detected.
+        /// </summary>
         event EventHandler<DetectMsiFeatureEventArgs> DetectMsiFeature;
+
+        /// <summary>
+        /// Fired when the detection for a specific package has begun.
+        /// </summary>
         event EventHandler<DetectPackageBeginEventArgs> DetectPackageBegin;
+
+        /// <summary>
+        /// Fired when the detection for a specific package has completed.
+        /// </summary>
         event EventHandler<DetectPackageCompleteEventArgs> DetectPackageComplete;
+
+        /// <summary>
+        /// Fired when a related bundle has been detected for a bundle.
+        /// </summary>
         event EventHandler<DetectRelatedBundleEventArgs> DetectRelatedBundle;
+
+        /// <summary>
+        /// Fired when a related MSI package has been detected for a package.
+        /// </summary>
         event EventHandler<DetectRelatedMsiPackageEventArgs> DetectRelatedMsiPackage;
+
+        /// <summary>
+        /// Fired when an MSP package detects a target MSI has been detected.
+        /// </summary>
         event EventHandler<DetectTargetMsiPackageEventArgs> DetectTargetMsiPackage;
+
+        /// <summary>
+        /// Fired when the update detection has found a potential update candidate.
+        /// </summary>
         event EventHandler<DetectUpdateEventArgs> DetectUpdate;
+
+        /// <summary>
+        /// Fired when the update detection phase has begun.
+        /// </summary>
         event EventHandler<DetectUpdateBeginEventArgs> DetectUpdateBegin;
+
+        /// <summary>
+        /// Fired when the update detection phase has completed.
+        /// </summary>
         event EventHandler<DetectUpdateCompleteEventArgs> DetectUpdateComplete;
+
+        /// <summary>
+        /// Fired when the engine is about to start the elevated process.
+        /// </summary>
         event EventHandler<ElevateBeginEventArgs> ElevateBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed starting the elevated process.
+        /// </summary>
         event EventHandler<ElevateCompleteEventArgs> ElevateComplete;
+
+        /// <summary>
+        /// Fired when the engine has encountered an error.
+        /// </summary>
         event EventHandler<ErrorEventArgs> Error;
+
+        /// <summary>
+        /// Fired when the engine has begun installing packages.
+        /// </summary>
         event EventHandler<ExecuteBeginEventArgs> ExecuteBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed installing packages.
+        /// </summary>
         event EventHandler<ExecuteCompleteEventArgs> ExecuteComplete;
+
+        /// <summary>
+        /// Fired when Windows Installer sends a files in use installation message.
+        /// </summary>
         event EventHandler<ExecuteFilesInUseEventArgs> ExecuteFilesInUse;
+
+        /// <summary>
+        /// Fired when Windows Installer sends an installation message.
+        /// </summary>
         event EventHandler<ExecuteMsiMessageEventArgs> ExecuteMsiMessage;
+
+        /// <summary>
+        /// Fired when the engine has begun installing a specific package.
+        /// </summary>
         event EventHandler<ExecutePackageBeginEventArgs> ExecutePackageBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed installing a specific package.
+        /// </summary>
         event EventHandler<ExecutePackageCompleteEventArgs> ExecutePackageComplete;
+
+        /// <summary>
+        /// Fired when the engine executes one or more patches targeting a product.
+        /// </summary>
         event EventHandler<ExecutePatchTargetEventArgs> ExecutePatchTarget;
+
+        /// <summary>
+        /// Fired by the engine while executing on payload.
+        /// </summary>
         event EventHandler<ExecuteProgressEventArgs> ExecuteProgress;
+
+        /// <summary>
+        /// Fired when the engine is about to launch the preapproved executable.
+        /// </summary>
         event EventHandler<LaunchApprovedExeBeginEventArgs> LaunchApprovedExeBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed launching the preapproved executable.
+        /// </summary>
         event EventHandler<LaunchApprovedExeCompleteEventArgs> LaunchApprovedExeComplete;
+
+        /// <summary>
+        /// Fired when the engine is about to pause Windows automatic updates.
+        /// </summary>
         event EventHandler<PauseAutomaticUpdatesBeginEventArgs> PauseAutomaticUpdatesBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed pausing Windows automatic updates.
+        /// </summary>
         event EventHandler<PauseAutomaticUpdatesCompleteEventArgs> PauseAutomaticUpdatesComplete;
+
+        /// <summary>
+        /// Fired when the engine has begun planning the installation.
+        /// </summary>
         event EventHandler<PlanBeginEventArgs> PlanBegin;
+
+        /// <summary>
+        /// Fired when the engine plans a new, compatible package using the same provider key.
+        /// </summary>
         event EventHandler<PlanCompatibleMsiPackageBeginEventArgs> PlanCompatibleMsiPackageBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed planning the installation of a specific package.
+        /// </summary>
         event EventHandler<PlanCompatibleMsiPackageCompleteEventArgs> PlanCompatibleMsiPackageComplete;
+
+        /// <summary>
+        /// Fired when the engine has completed planning the installation.
+        /// </summary>
         event EventHandler<PlanCompleteEventArgs> PlanComplete;
+
+        /// <summary>
+        /// Fired when the engine is about to plan a feature in an MSI package.
+        /// </summary>
         event EventHandler<PlanMsiFeatureEventArgs> PlanMsiFeature;
+
+        /// <summary>
+        /// Fired when the engine is planning an MSI or MSP package.
+        /// </summary>
         event EventHandler<PlanMsiPackageEventArgs> PlanMsiPackage;
+
+        /// <summary>
+        /// Fired when the engine has begun planning the installation of a specific package.
+        /// </summary>
         event EventHandler<PlanPackageBeginEventArgs> PlanPackageBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed planning the installation of a specific package.
+        /// </summary>
         event EventHandler<PlanPackageCompleteEventArgs> PlanPackageComplete;
+
+        /// <summary>
+        /// Fired when the engine has begun planning for a related bundle.
+        /// </summary>
         event EventHandler<PlanRelatedBundleEventArgs> PlanRelatedBundle;
+
+        /// <summary>
+        /// Fired when the engine is about to plan the target MSI of a MSP package.
+        /// </summary>
         event EventHandler<PlanTargetMsiPackageEventArgs> PlanTargetMsiPackage;
+
+        /// <summary>
+        /// Fired when the engine has changed progress for the bundle installation.
+        /// </summary>
         event EventHandler<ProgressEventArgs> Progress;
+
+        /// <summary>
+        /// Fired when the engine has begun registering the location and visibility of the bundle.
+        /// </summary>
         event EventHandler<RegisterBeginEventArgs> RegisterBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed registering the location and visibility of the bundle.
+        /// </summary>
         event EventHandler<RegisterCompleteEventArgs> RegisterComplete;
+
+        /// <summary>
+        /// Fired by the engine to allow the BA to change the source
+        /// using <see cref="IEngine.SetLocalSource(string, string, string)"/> or <see cref="IEngine.SetDownloadSource(string, string, string, string, string)"/>.
+        /// </summary>
         event EventHandler<ResolveSourceEventArgs> ResolveSource;
+
+        /// <summary>
+        /// Fired when the engine is about to rollback an MSI transaction.
+        /// </summary>
         event EventHandler<RollbackMsiTransactionBeginEventArgs> RollbackMsiTransactionBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed rolling back an MSI transaction.
+        /// </summary>
         event EventHandler<RollbackMsiTransactionCompleteEventArgs> RollbackMsiTransactionComplete;
+
+        /// <summary>
+        /// Fired when the engine is shutting down the bootstrapper application.
+        /// </summary>
         event EventHandler<ShutdownEventArgs> Shutdown;
+
+        /// <summary>
+        /// Fired when the engine is starting up the bootstrapper application.
+        /// </summary>
         event EventHandler<StartupEventArgs> Startup;
+
+        /// <summary>
+        /// Fired when the engine is about to take a system restore point.
+        /// </summary>
         event EventHandler<SystemRestorePointBeginEventArgs> SystemRestorePointBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed taking a system restore point.
+        /// </summary>
         event EventHandler<SystemRestorePointCompleteEventArgs> SystemRestorePointComplete;
+
+        /// <summary>
+        /// Fired when the system is shutting down or user is logging off.
+        /// </summary>
+        /// <remarks>
+        /// <para>To prevent shutting down or logging off, set <see cref="CancellableHResultEventArgs.Cancel"/> to
+        /// true; otherwise, set it to false.</para>
+        /// <para>By default setup will prevent shutting down or logging off between
+        /// <see cref="IDefaultBootstrapperApplication.ApplyBegin"/> and <see cref="IDefaultBootstrapperApplication.ApplyComplete"/>.
+        /// Derivatives can change this behavior by handling <see cref="IDefaultBootstrapperApplication.SystemShutdown"/>.</para>
+        /// <para>If <see cref="SystemShutdownEventArgs.Reasons"/> contains <see cref="EndSessionReasons.Critical"/>
+        /// the bootstrapper cannot prevent the shutdown and only has a few seconds to save state or perform any other
+        /// critical operations before being closed by the operating system.</para>
+        /// <para>This event may be fired on a different thread.</para>
+        /// </remarks>
         event EventHandler<SystemShutdownEventArgs> SystemShutdown;
+
+        /// <summary>
+        /// Fired when the engine has begun removing the registration for the location and visibility of the bundle.
+        /// </summary>
         event EventHandler<UnregisterBeginEventArgs> UnregisterBegin;
+
+        /// <summary>
+        /// Fired when the engine has completed removing the registration for the location and visibility of the bundle.
+        /// </summary>
         event EventHandler<UnregisterCompleteEventArgs> UnregisterComplete;
     }
 }
\ No newline at end of file
diff --git a/src/WixToolset.Mba.Core/IEngine.cs b/src/WixToolset.Mba.Core/IEngine.cs
index 8403352d..0899ec43 100644
--- a/src/WixToolset.Mba.Core/IEngine.cs
+++ b/src/WixToolset.Mba.Core/IEngine.cs
@@ -6,6 +6,9 @@ namespace WixToolset.Mba.Core
     using System.ComponentModel;
     using System.Security;
 
+    /// <summary>
+    /// High level abstraction over the <see cref="IBootstrapperEngine"/> interface.
+    /// </summary>
     public interface IEngine
     {
         /// <summary>
diff --git a/src/WixToolset.Mba.Core/IPackageInfo.cs b/src/WixToolset.Mba.Core/IPackageInfo.cs
index a82e81ea..0d7e549e 100644
--- a/src/WixToolset.Mba.Core/IPackageInfo.cs
+++ b/src/WixToolset.Mba.Core/IPackageInfo.cs
@@ -2,23 +2,89 @@
 
 namespace WixToolset.Mba.Core
 {
+    /// <summary>
+    /// Package information from the BA manifest.
+    /// </summary>
     public interface IPackageInfo
     {
+        /// <summary>
+        /// 
+        /// </summary>
         CacheType CacheType { get; }
+
+        /// <summary>
+        /// Place for the BA to store it's own custom data for this package.
+        /// </summary>
         object CustomData { get; set; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         string Description { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         string DisplayInternalUICondition { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         string DisplayName { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         string Id { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         string InstallCondition { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         bool Permanent { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         bool PrereqPackage { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         string PrereqLicenseFile { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         string PrereqLicenseUrl { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         string ProductCode { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         PackageType Type { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         string UpgradeCode { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         string Version { get; }
+
+        /// <summary>
+        /// 
+        /// </summary>
         bool Vital { get; }
     }
 }
\ No newline at end of file
diff --git a/src/WixToolset.Mba.Core/PackageInfo.cs b/src/WixToolset.Mba.Core/PackageInfo.cs
index d54438f5..75a0fd53 100644
--- a/src/WixToolset.Mba.Core/PackageInfo.cs
+++ b/src/WixToolset.Mba.Core/PackageInfo.cs
@@ -7,46 +7,133 @@ namespace WixToolset.Mba.Core
     using System.Xml;
     using System.Xml.XPath;
 
+    /// <summary>
+    /// 
+    /// </summary>
     public enum CacheType
     {
+        /// <summary>
+        /// 
+        /// </summary>
         No,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Yes,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Always,
     }
 
+    /// <summary>
+    /// 
+    /// </summary>
     public enum PackageType
     {
+        /// <summary>
+        /// 
+        /// </summary>
         Unknown,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Exe,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Msi,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Msp,
+
+        /// <summary>
+        /// 
+        /// </summary>
         Msu,
+
+        /// <summary>
+        /// 
+        /// </summary>
         UpgradeBundle,
+
+        /// <summary>
+        /// 
+        /// </summary>
         AddonBundle,
+
+        /// <summary>
+        /// 
+        /// </summary>
         PatchBundle,
     }
 
+    /// <summary>
+    /// Default implementation of <see cref="IPackageInfo"/>.
+    /// </summary>
     public class PackageInfo : IPackageInfo
     {
+        /// <inheritdoc/>
         public string Id { get; internal set; }
+
+        /// <inheritdoc/>
         public string DisplayName { get; internal set; }
+
+        /// <inheritdoc/>
         public string Description { get; internal set; }
+
+        /// <inheritdoc/>
         public PackageType Type { get; internal set; }
+
+        /// <inheritdoc/>
         public bool Permanent { get; internal set; }
+
+        /// <inheritdoc/>
         public bool Vital { get; internal set; }
+
+        /// <inheritdoc/>
         public string DisplayInternalUICondition { get; internal set; }
+
+        /// <inheritdoc/>
         public string ProductCode { get; internal set; }
+
+        /// <inheritdoc/>
         public string UpgradeCode { get; internal set; }
+
+        /// <inheritdoc/>
         public string Version { get; internal set; }
+
+        /// <inheritdoc/>
         public string InstallCondition { get; internal set; }
+
+        /// <inheritdoc/>
         public CacheType CacheType { get; internal set; }
+
+        /// <inheritdoc/>
         public bool PrereqPackage { get; internal set; }
+
+        /// <inheritdoc/>
         public string PrereqLicenseFile { get; internal set; }
+
+        /// <inheritdoc/>
         public string PrereqLicenseUrl { get; internal set; }
+
+        /// <inheritdoc/>
         public object CustomData { get; set; }
 
         internal PackageInfo() { }
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="root"></param>
+        /// <returns></returns>
         public static IDictionary<string, IPackageInfo> ParsePackagesFromXml(XPathNavigator root)
         {
             var packagesById = new Dictionary<string, IPackageInfo>();
@@ -105,6 +192,12 @@ namespace WixToolset.Mba.Core
             return packagesById;
         }
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="node"></param>
+        /// <param name="attributeName"></param>
+        /// <returns></returns>
         public static CacheType? GetCacheTypeAttribute(XPathNavigator node, string attributeName)
         {
             string attributeValue = BootstrapperApplicationData.GetAttribute(node, attributeName);
@@ -128,6 +221,12 @@ namespace WixToolset.Mba.Core
             }
         }
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="node"></param>
+        /// <param name="attributeName"></param>
+        /// <returns></returns>
         public static PackageType? GetPackageTypeAttribute(XPathNavigator node, string attributeName)
         {
             string attributeValue = BootstrapperApplicationData.GetAttribute(node, attributeName);
@@ -159,6 +258,14 @@ namespace WixToolset.Mba.Core
             }
         }
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="id"></param>
+        /// <param name="relationType"></param>
+        /// <param name="perMachine"></param>
+        /// <param name="version"></param>
+        /// <returns></returns>
         public static IPackageInfo GetRelatedBundleAsPackage(string id, RelationType relationType, bool perMachine, string version)
         {
             PackageInfo package = new PackageInfo();
diff --git a/src/WixToolset.Mba.Core/VerUtil.cs b/src/WixToolset.Mba.Core/VerUtil.cs
index dcc9dee2..81c5b716 100644
--- a/src/WixToolset.Mba.Core/VerUtil.cs
+++ b/src/WixToolset.Mba.Core/VerUtil.cs
@@ -6,6 +6,9 @@ namespace WixToolset.Mba.Core
     using System.Runtime.InteropServices;
     using System.Text;
 
+    /// <summary>
+    /// Managed wrapper for verutil.
+    /// </summary>
     public static class VerUtil
     {
         [DllImport("mbanative.dll", ExactSpelling = true, PreserveSig = false)]
@@ -105,18 +108,34 @@ namespace WixToolset.Mba.Core
             return VerCompareStringVersions(version1, version2, strict);
         }
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="version"></param>
+        /// <returns></returns>
         public static VerUtilVersion CopyVersion(VerUtilVersion version)
         {
             var handle = VerCopyVersion(version.GetHandle());
             return new VerUtilVersion(handle);
         }
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="version"></param>
+        /// <param name="strict">Whether to throw exception on invalid version.</param>
+        /// <returns></returns>
         public static VerUtilVersion ParseVersion(string version, bool strict)
         {
             var handle = VerParseVersion(version, 0, strict);
             return new VerUtilVersion(handle);
         }
 
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="version"></param>
+        /// <returns></returns>
         public static VerUtilVersion VersionFromQword(long version)
         {
             var handle = VerVersionFromQword(version);
diff --git a/src/WixToolset.Mba.Core/VerUtilVersion.cs b/src/WixToolset.Mba.Core/VerUtilVersion.cs
index 2b509a21..7408c26f 100644
--- a/src/WixToolset.Mba.Core/VerUtilVersion.cs
+++ b/src/WixToolset.Mba.Core/VerUtilVersion.cs
@@ -5,6 +5,9 @@ namespace WixToolset.Mba.Core
     using System;
     using System.Runtime.InteropServices;
 
+    /// <summary>
+    /// An enhanced implementation of SemVer 2.0.
+    /// </summary>
     public sealed class VerUtilVersion : IDisposable
     {
         internal VerUtilVersion(VerUtil.VersionHandle handle)
@@ -30,15 +33,48 @@ namespace WixToolset.Mba.Core
             }
         }
 
+        /// <summary>
+        /// String version, which would have stripped the leading 'v'.
+        /// </summary>
         public string Version { get; private set; }
+
+        /// <summary>
+        /// For version A.B.C.D, Major is A. It is 0 if not specified.
+        /// </summary>
         public uint Major { get; private set; }
+
+        /// <summary>
+        /// For version A.B.C.D, Minor is B. It is 0 if not specified.
+        /// </summary>
         public uint Minor { get; private set; }
+
+        /// <summary>
+        /// For version A.B.C.D, Patch is C. It is 0 if not specified.
+        /// </summary>
         public uint Patch { get; private set; }
+
+        /// <summary>
+        /// For version A.B.C.D, Revision is D. It is 0 if not specified.
+        /// </summary>
         public uint Revision { get; private set; }
+
+        /// <summary>
+        /// For version X.Y.Z-releaselabels+metadata, ReleaseLabels is the parsed information for releaselabels.
+        /// </summary>
         public VerUtilVersionReleaseLabel[] ReleaseLabels { get; private set; }
+
+        /// <summary>
+        /// For version X.Y.Z-releaselabels+metadata, Metadata is the rest of the string after +.
+        /// For invalid versions, it is all of the string after the point where it was an invalid string.
+        /// </summary>
         public string Metadata { get; private set; }
+
+        /// <summary>
+        /// Whether the version conformed to the spec.
+        /// </summary>
         public bool IsInvalid { get; private set; }
 
+        /// <inheritdoc/>
         public void Dispose()
         {
             if (this.Handle != null)
diff --git a/src/WixToolset.Mba.Core/VerUtilVersionReleaseLabel.cs b/src/WixToolset.Mba.Core/VerUtilVersionReleaseLabel.cs
index 84ff3b36..97e8190d 100644
--- a/src/WixToolset.Mba.Core/VerUtilVersionReleaseLabel.cs
+++ b/src/WixToolset.Mba.Core/VerUtilVersionReleaseLabel.cs
@@ -5,6 +5,9 @@ namespace WixToolset.Mba.Core
     using System;
     using System.Runtime.InteropServices;
 
+    /// <summary>
+    /// A release label from a <see cref="VerUtilVersion"/>.
+    /// </summary>
     public sealed class VerUtilVersionReleaseLabel
     {
         internal VerUtilVersionReleaseLabel(IntPtr pReleaseLabel, IntPtr wzVersion)
@@ -15,8 +18,19 @@ namespace WixToolset.Mba.Core
             this.Label = VerUtil.VersionStringFromOffset(wzVersion, releaseLabel.cchLabelOffset, releaseLabel.cchLabel);
         }
 
+        /// <summary>
+        /// Whether the label was parsed as a number.
+        /// </summary>
         public bool IsNumeric { get; private set; }
+
+        /// <summary>
+        /// If <see cref="IsNumeric"/> then the value that was parsed.
+        /// </summary>
         public uint Value { get; private set; }
+
+        /// <summary>
+        /// The string version of the label.
+        /// </summary>
         public string Label { get; private set; }
     }
 }
diff --git a/src/WixToolset.Mba.Core/WixToolset.Mba.Core.csproj b/src/WixToolset.Mba.Core/WixToolset.Mba.Core.csproj
index 2ca3d2d9..1cfc8c11 100644
--- a/src/WixToolset.Mba.Core/WixToolset.Mba.Core.csproj
+++ b/src/WixToolset.Mba.Core/WixToolset.Mba.Core.csproj
@@ -10,11 +10,7 @@
     <Description>Managed Bootstrapper Application Core</Description>
     <NuspecFile>$(MSBuildThisFileName).nuspec</NuspecFile>
     <IncludeSymbols>true</IncludeSymbols>
-    <NBGV_EmitThisAssemblyClass>false</NBGV_EmitThisAssemblyClass>
-  </PropertyGroup>
-
-  <PropertyGroup Condition=" '$(UsingMicrosoftNETSdk)'!='true' and '$(CreateDocumentation)'!='false' ">
-    <DocumentationFile>$(OutputPath)\$(AssemblyName).xml</DocumentationFile>
+    <CreateDocumentationFile>true</CreateDocumentationFile>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/WixToolset.Mba.Core/WixToolset.Mba.Core.nuspec b/src/WixToolset.Mba.Core/WixToolset.Mba.Core.nuspec
index cf7d014d..a5e09ea9 100644
--- a/src/WixToolset.Mba.Core/WixToolset.Mba.Core.nuspec
+++ b/src/WixToolset.Mba.Core/WixToolset.Mba.Core.nuspec
@@ -19,7 +19,9 @@
 
   <files>
     <file src="net20\$id$.dll" target="lib\net20" />
+    <file src="net20\$id$.xml" target="lib\net20" />
     <file src="netstandard2.0\$id$.dll" target="lib\netstandard2.0" />
+    <file src="netstandard2.0\$id$.xml" target="lib\netstandard2.0" />
 
     <file src="v142\ARM64\mbanative.dll" target="runtimes\win-arm64\native" />
     <file src="v142\ARM64\mbanative.pdb" target="runtimes\win-arm64\native" />
diff --git a/src/test/WixToolsetTest.Mba.Core/BaseBootstrapperApplicationFactoryFixture.cs b/src/test/WixToolsetTest.Mba.Core/BaseBootstrapperApplicationFactoryFixture.cs
index 7fe0a405..aaf5ee29 100644
--- a/src/test/WixToolsetTest.Mba.Core/BaseBootstrapperApplicationFactoryFixture.cs
+++ b/src/test/WixToolsetTest.Mba.Core/BaseBootstrapperApplicationFactoryFixture.cs
@@ -103,6 +103,25 @@ namespace WixToolsetTest.Mba.Core
         }
 
         [StructLayout(LayoutKind.Sequential)]
+        public struct BootstrapperCreateArgs
+        {
+            [MarshalAs(UnmanagedType.I4)] public readonly int cbSize;
+            [MarshalAs(UnmanagedType.I8)] public readonly long qwEngineAPIVersion;
+            public readonly IntPtr pfnBootstrapperEngineProc;
+            public readonly IntPtr pvBootstrapperEngineProcContext;
+            public readonly IntPtr pCommand;
+
+            public BootstrapperCreateArgs(long version, IntPtr pEngineProc, IntPtr pEngineContext, IntPtr pCommand)
+            {
+                this.cbSize = Marshal.SizeOf(typeof(BootstrapperCreateArgs));
+                this.qwEngineAPIVersion = version;
+                this.pfnBootstrapperEngineProc = pEngineProc;
+                this.pvBootstrapperEngineProcContext = pEngineContext;
+                this.pCommand = pCommand;
+            }
+        }
+
+        [StructLayout(LayoutKind.Sequential)]
         public struct TestCreateResults
         {
             public int cbSize;