16 files changed, 228 insertions, 38 deletions

diff --git a/src/api/burn/WixToolset.BootstrapperApplicationApi/Engine.cs b/src/api/burn/WixToolset.BootstrapperApplicationApi/Engine.cs
index 44d77359..25413790 100644
--- a/src/api/burn/WixToolset.BootstrapperApplicationApi/Engine.cs
+++ b/src/api/burn/WixToolset.BootstrapperApplicationApi/Engine.cs
@@ -259,9 +259,9 @@ namespace WixToolset.BootstrapperApplicationApi
         }
 
         /// <inheritdoc/>
-        public void SetUpdateSource(string url)
+        public void SetUpdateSource(string url, string authorizationHeader)
         {
-            this.engine.SetUpdateSource(url);
+            this.engine.SetUpdateSource(url, authorizationHeader);
         }
 
         /// <inheritdoc/>
@@ -271,9 +271,9 @@ namespace WixToolset.BootstrapperApplicationApi
         }
 
         /// <inheritdoc/>
-        public void SetDownloadSource(string packageOrContainerId, string payloadId, string url, string user, string password)
+        public void SetDownloadSource(string packageOrContainerId, string payloadId, string url, string user, string password, string authorizationHeader)
         {
-            this.engine.SetDownloadSource(packageOrContainerId, payloadId, url, user, password);
+            this.engine.SetDownloadSource(packageOrContainerId, payloadId, url, user, password, authorizationHeader);
         }
 
         /// <inheritdoc/>
diff --git a/src/api/burn/WixToolset.BootstrapperApplicationApi/IBootstrapperEngine.cs b/src/api/burn/WixToolset.BootstrapperApplicationApi/IBootstrapperEngine.cs
index c7b0c003..13702757 100644
--- a/src/api/burn/WixToolset.BootstrapperApplicationApi/IBootstrapperEngine.cs
+++ b/src/api/burn/WixToolset.BootstrapperApplicationApi/IBootstrapperEngine.cs
@@ -129,14 +129,15 @@ namespace WixToolset.BootstrapperApplicationApi
             );
 
         /// <summary>
-        /// See <see cref="IEngine.SetDownloadSource(string, string, string, string, string)"/>.
+        /// See <see cref="IEngine.SetDownloadSource(string, string, string, string, string, string)"/>.
         /// </summary>
         void SetDownloadSource(
             [MarshalAs(UnmanagedType.LPWStr)] string wzPackageOrContainerId,
             [MarshalAs(UnmanagedType.LPWStr)] string wzPayloadId,
             [MarshalAs(UnmanagedType.LPWStr)] string wzUrl,
             [MarshalAs(UnmanagedType.LPWStr)] string wzUser,
-            [MarshalAs(UnmanagedType.LPWStr)] string wzPassword
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPassword,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzAuthorizationHeader
             );
 
         /// <summary>
@@ -219,7 +220,8 @@ namespace WixToolset.BootstrapperApplicationApi
         /// Sets the URL to the update feed.
         /// </summary>
         void SetUpdateSource(
-            [MarshalAs(UnmanagedType.LPWStr)] string url
+            [MarshalAs(UnmanagedType.LPWStr)] string url,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzAuthorizationHeader
             );
 
         /// <summary>
diff --git a/src/api/burn/WixToolset.BootstrapperApplicationApi/IDefaultBootstrapperApplication.cs b/src/api/burn/WixToolset.BootstrapperApplicationApi/IDefaultBootstrapperApplication.cs
index ad51b2be..1ff12c28 100644
--- a/src/api/burn/WixToolset.BootstrapperApplicationApi/IDefaultBootstrapperApplication.cs
+++ b/src/api/burn/WixToolset.BootstrapperApplicationApi/IDefaultBootstrapperApplication.cs
@@ -37,14 +37,14 @@ namespace WixToolset.BootstrapperApplicationApi
         /// <summary>
         /// Fired when the engine has begun acquiring the payload or container.
         /// The BA can change the source using <see cref="IEngine.SetLocalSource(String, String, String)"/>
-        /// or <see cref="IEngine.SetDownloadSource(String, String, String, String, String)"/>.
+        /// or <see cref="IEngine.SetDownloadSource(String, String, String, String, String, String)"/>.
         /// </summary>
         event EventHandler<CacheAcquireBeginEventArgs> CacheAcquireBegin;
 
         /// <summary>
         /// Fired when the engine has completed the acquisition of the payload or container.
         /// The BA can change the source using <see cref="IEngine.SetLocalSource(String, String, String)"/>
-        /// or <see cref="IEngine.SetDownloadSource(String, String, String, String, String)"/>.
+        /// or <see cref="IEngine.SetDownloadSource(String, String, String, String, String, String)"/>.
         /// </summary>
         event EventHandler<CacheAcquireCompleteEventArgs> CacheAcquireComplete;
 
diff --git a/src/api/burn/WixToolset.BootstrapperApplicationApi/IEngine.cs b/src/api/burn/WixToolset.BootstrapperApplicationApi/IEngine.cs
index bd78409b..03ceed06 100644
--- a/src/api/burn/WixToolset.BootstrapperApplicationApi/IEngine.cs
+++ b/src/api/burn/WixToolset.BootstrapperApplicationApi/IEngine.cs
@@ -156,7 +156,8 @@ namespace WixToolset.BootstrapperApplicationApi
         /// Sets the URL to the update feed.
         /// </summary>
         /// <param name="url">URL of the update feed.</param>
-        void SetUpdateSource(string url);
+        /// <param name="authorizationHeader">Additional proxy authentication header. Not currently used.</param>
+        void SetUpdateSource(string url, string authorizationHeader);
 
         /// <summary>
         /// Set the local source for a package or container.
@@ -174,7 +175,8 @@ namespace WixToolset.BootstrapperApplicationApi
         /// <param name="url">The new url.</param>
         /// <param name="user">The user name for proxy authentication.</param>
         /// <param name="password">The password for proxy authentication.</param>
-        void SetDownloadSource(string packageOrContainerId, string payloadId, string url, string user, string password);
+        /// <param name="authorizationHeader">Additional proxy authentication header. Not currently used.</param>
+        void SetDownloadSource(string packageOrContainerId, string payloadId, string url, string user, string password, string authorizationHeader);
 
         /// <summary>
         /// Sets numeric variables for the engine.
diff --git a/src/api/burn/WixToolset.BootstrapperApplicationApi/README.md b/src/api/burn/WixToolset.BootstrapperApplicationApi/README.md
new file mode 100644
index 00000000..eeedbf9f
--- /dev/null
+++ b/src/api/burn/WixToolset.BootstrapperApplicationApi/README.md
@@ -0,0 +1,37 @@
+# WixToolset.BootstrapperApplicationApi - managed BootstrapperApplication API
+
+The `WixToolset.BootstrapperApplicationApi` package contains the SDK for building managed BootstrapperApplications.
+
+[Web Site][web] | [Documentation][docs] | [Issue Tracker][issues] | [Discussions][discussions]
+
+
+## Open Source Maintenance Fee
+
+To ensure the long-term sustainability of this project, users of this package who generate revenue must pay an [Open Source Maintenance Fee][osmf]. While the source code is freely available under the terms of the [LICENSE][license], this package and other aspects of the project require [adherence to the Open Source Maintenance Fee EULA][eula].
+
+To pay the Maintenance Fee, [become a Sponsor](https://github.com/sponsors/wixtoolset).
+
+
+## Getting started
+
+BAFunctions are native-code DLLs (typically written in C++) that let you supplement the behavior of WixStdBA, rather than writing an entirely new BA to tweak existing BA behavior.
+
+The best way to learn is via the samples at: https://github.com/wixtoolset/wix/tree/HEAD/src/ext/Bal/Samples/bafunctions
+
+
+## Additional resources
+
+* [WiX Website][web]
+* [WiX Documentation][docs]
+* [WiX Issue Tracker][issues]
+* [WiX Discussions][discussions]
+
+
+[web]: https://www.firegiant.com/wixtoolset/
+[docs]: https://docs.firegiant.com/wixtoolset/
+[issues]: https://github.com/wixtoolset/issues/issues
+[discussions]: https://github.com/orgs/wixtoolset/discussions
+[sdk]: https://www.nuget.org/packages/WixToolset.Sdk/
+[osmf]: https://opensourcemaintenancefee.org/
+[license]: https://github.com/wixtoolset/wix/blob/main/LICENSE.TXT
+[eula]: https://github.com/wixtoolset/wix/blob/main/OSMFEULA.txt
diff --git a/src/api/burn/WixToolset.BootstrapperApplicationApi/WixToolset.BootstrapperApplicationApi.nuspec b/src/api/burn/WixToolset.BootstrapperApplicationApi/WixToolset.BootstrapperApplicationApi.nuspec
index 63acc895..73fef99b 100644
--- a/src/api/burn/WixToolset.BootstrapperApplicationApi/WixToolset.BootstrapperApplicationApi.nuspec
+++ b/src/api/burn/WixToolset.BootstrapperApplicationApi/WixToolset.BootstrapperApplicationApi.nuspec
@@ -7,6 +7,7 @@
     <description>$description$</description>
     <authors>$authors$</authors>
     <icon>icon.png</icon>
+    <readme>README.md</readme>
     <license type="file">OSMFEULA.txt</license>
     <requireLicenseAcceptance>true</requireLicenseAcceptance>
     <tags>$packageTags$</tags>
@@ -25,6 +26,7 @@
   <files>
     <file src="$eulaTxt$" />
     <file src="$iconPng$" />
+    <file src="$projectFolder$\README.md" />
 
     <file src="$projectFolder$\build\WixToolset.BootstrapperApplicationApi.props" target="build\" />
 
diff --git a/src/api/burn/bextutil/README.md b/src/api/burn/bextutil/README.md
new file mode 100644
index 00000000..cee7e98c
--- /dev/null
+++ b/src/api/burn/bextutil/README.md
@@ -0,0 +1,30 @@
+# WixToolset.BootstrapperExtensionApi - extend WiX Bootstrapper Engine
+
+The `WixToolset.BootstrapperExtensionApi` package contains the SDK for extending the WiX Bootstrapper Engine, better known as "burn".
+
+[Web Site][web] | [Documentation][docs] | [Issue Tracker][issues] | [Discussions][discussions]
+
+
+## Open Source Maintenance Fee
+
+To ensure the long-term sustainability of this project, users of this package who generate revenue must pay an [Open Source Maintenance Fee][osmf]. While the source code is freely available under the terms of the [LICENSE][license], this package and other aspects of the project require [adherence to the Open Source Maintenance Fee EULA][eula].
+
+To pay the Maintenance Fee, [become a Sponsor](https://github.com/sponsors/wixtoolset).
+
+
+## Additional resources
+
+* [WiX Website][web]
+* [WiX Documentation][docs]
+* [WiX Issue Tracker][issues]
+* [WiX Discussions][discussions]
+
+
+[web]: https://www.firegiant.com/wixtoolset/
+[docs]: https://docs.firegiant.com/wixtoolset/
+[issues]: https://github.com/wixtoolset/issues/issues
+[discussions]: https://github.com/orgs/wixtoolset/discussions
+[sdk]: https://www.nuget.org/packages/WixToolset.Sdk/
+[osmf]: https://opensourcemaintenancefee.org/
+[license]: https://github.com/wixtoolset/wix/blob/main/LICENSE.TXT
+[eula]: https://github.com/wixtoolset/wix/blob/main/OSMFEULA.txt
diff --git a/src/api/burn/bextutil/bextutil.nuspec b/src/api/burn/bextutil/bextutil.nuspec
index f790e0b8..065b72a3 100644
--- a/src/api/burn/bextutil/bextutil.nuspec
+++ b/src/api/burn/bextutil/bextutil.nuspec
@@ -7,6 +7,7 @@
     <description>$description$</description>
     <authors>$authors$</authors>
     <icon>icon.png</icon>
+    <readme>README.md</readme>
     <license type="file">OSMFEULA.txt</license>
     <requireLicenseAcceptance>true</requireLicenseAcceptance>
     <tags>$packageTags$</tags>
@@ -21,6 +22,7 @@
   <files>
     <file src="$eulaTxt$" />
     <file src="$iconPng$" />
+    <file src="$projectFolder$\README.md" />
     <file src="$projectFolder$\build\$id$.props" target="build\" />
     <file src="$projectFolder$\inc\*" target="build\native\include" />
     <file src="$projectFolder$\..\inc\BootstrapperExtensionTypes.h" target="build\native\include" />
diff --git a/src/api/wix/WixToolset.Data/ErrorMessages.cs b/src/api/wix/WixToolset.Data/ErrorMessages.cs
index ef70ebc4..23ba5151 100644
--- a/src/api/wix/WixToolset.Data/ErrorMessages.cs
+++ b/src/api/wix/WixToolset.Data/ErrorMessages.cs
@@ -248,11 +248,6 @@ namespace WixToolset.Data
             return Message(sourceLineNumbers, Ids.DuplicateCabinetName2, "Duplicate cabinet name '{0}' error related to previous error.", cabinetName);
         }
 
-        public static Message DuplicateCommandLineOptionInExtension(string arg)
-        {
-            return Message(null, Ids.DuplicateCommandLineOptionInExtension, "The command line option '{0}' has already been loaded by another Heat extension.", arg);
-        }
-
         public static Message DuplicateComponentGuids(SourceLineNumber sourceLineNumbers, string componentId, string guid, string type, string keyPath)
         {
             return Message(sourceLineNumbers, Ids.DuplicateComponentGuids, "Component/@Id='{0}' with {2} '{3}' has a @Guid value '{1}' that duplicates another component in this package. It is recommended to give each component its own unique GUID.", componentId, guid, type, keyPath);
@@ -295,7 +290,7 @@ namespace WixToolset.Data
 
         public static Message DuplicateLocalizationIdentifier(SourceLineNumber sourceLineNumbers, string localizationId)
         {
-            return Message(sourceLineNumbers, Ids.DuplicateLocalizationIdentifier, "The localization identifier '{0}' has been duplicated in multiple locations. Please resolve the conflict.", localizationId);
+            return Message(sourceLineNumbers, Ids.DuplicateLocalizationIdentifier, "The localization identifier '{0}' has been duplicated in multiple locations. A common cause is a bundle .wixproj that automatically loads .wxl files that are intended for the bootstrapper application. You can turn off that behavior by setting the EnableDefaultEmbeddedResourceItems property to false.", localizationId);
         }
 
         public static Message DuplicateModuleCaseInsensitiveFileIdentifier(SourceLineNumber sourceLineNumbers, string moduleId, string fileId1, string fileId2)
@@ -705,16 +700,6 @@ namespace WixToolset.Data
             return Message(null, Ids.HarvestSourceNotSpecified, "A harvest source must be specified after the harvest type and can be followed by harvester arguments.");
         }
 
-        public static Message HarvestTypeNotFound()
-        {
-            return Message(null, Ids.HarvestTypeNotFound, "The harvest type was not found in the list of loaded Heat extensions.");
-        }
-
-        public static Message HarvestTypeNotFound(string harvestType)
-        {
-            return Message(null, Ids.HarvestTypeNotFound, "The harvest type '{0}' was specified. Harvest types cannot start with a '-'. Remove the '-' to specify a valid harvest type.", harvestType);
-        }
-
         public static Message IdentifierNotFound(string type, string identifier)
         {
             return Message(null, Ids.IdentifierNotFound, "An expected identifier ('{1}', of type '{0}') was not found.", type, identifier);
@@ -2588,8 +2573,6 @@ namespace WixToolset.Data
             SameFileIdDifferentSource = 317,
             HarvestSourceNotSpecified = 318,
             OutputTargetNotSpecified = 319,
-            DuplicateCommandLineOptionInExtension = 320,
-            HarvestTypeNotFound = 321,
             BothUpgradeCodesRequired = 322,
             IllegalBinderClassName = 323,
             SpecifiedBinderNotFound = 324,
diff --git a/src/api/wix/WixToolset.Data/README.md b/src/api/wix/WixToolset.Data/README.md
new file mode 100644
index 00000000..192e7993
--- /dev/null
+++ b/src/api/wix/WixToolset.Data/README.md
@@ -0,0 +1,30 @@
+# WixToolset.Data - fundamental data types for the WiX Toolset
+
+The `WixToolset.Data` package provides the fundamental data types used throughout the WiX Toolset.
+
+[Web Site][web] | [Documentation][docs] | [Issue Tracker][issues] | [Discussions][discussions]
+
+
+## Open Source Maintenance Fee
+
+To ensure the long-term sustainability of this project, users of this package who generate revenue must pay an [Open Source Maintenance Fee][osmf]. While the source code is freely available under the terms of the [LICENSE][license], this package and other aspects of the project require [adherence to the Open Source Maintenance Fee EULA][eula].
+
+To pay the Maintenance Fee, [become a Sponsor](https://github.com/sponsors/wixtoolset).
+
+
+## Additional resources
+
+* [WiX Website][web]
+* [WiX Documentation][docs]
+* [WiX Issue Tracker][issues]
+* [WiX Discussions][discussions]
+
+
+[web]: https://www.firegiant.com/wixtoolset/
+[docs]: https://docs.firegiant.com/wixtoolset/
+[issues]: https://github.com/wixtoolset/issues/issues
+[discussions]: https://github.com/orgs/wixtoolset/discussions
+[sdk]: https://www.nuget.org/packages/WixToolset.Sdk/
+[osmf]: https://opensourcemaintenancefee.org/
+[license]: https://github.com/wixtoolset/wix/blob/main/LICENSE.TXT
+[eula]: https://github.com/wixtoolset/wix/blob/main/OSMFEULA.txt
diff --git a/src/api/wix/WixToolset.Data/Symbols/HarvestPayloadsSymbol.cs b/src/api/wix/WixToolset.Data/Symbols/HarvestPayloadsSymbol.cs
new file mode 100644
index 00000000..976214dd
--- /dev/null
+++ b/src/api/wix/WixToolset.Data/Symbols/HarvestPayloadsSymbol.cs
@@ -0,0 +1,68 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Data
+{
+    using WixToolset.Data.Symbols;
+
+    public static partial class SymbolDefinitions
+    {
+        public static readonly IntermediateSymbolDefinition HarvestPayloads = new IntermediateSymbolDefinition(
+            SymbolDefinitionType.HarvestPayloads,
+            new[]
+            {
+                new IntermediateFieldDefinition(nameof(HarvestPayloadsSymbolFields.Inclusions), IntermediateFieldType.String),
+                new IntermediateFieldDefinition(nameof(HarvestPayloadsSymbolFields.Exclusions), IntermediateFieldType.String),
+                new IntermediateFieldDefinition(nameof(HarvestPayloadsSymbolFields.ComplexReferenceParentType), IntermediateFieldType.String),
+                new IntermediateFieldDefinition(nameof(HarvestPayloadsSymbolFields.ParentId), IntermediateFieldType.String),
+            },
+            typeof(HarvestPayloadsSymbol));
+    }
+}
+
+namespace WixToolset.Data.Symbols
+{
+    public enum HarvestPayloadsSymbolFields
+    {
+        Inclusions,
+        Exclusions,
+        ComplexReferenceParentType,
+        ParentId,
+    }
+
+    public class HarvestPayloadsSymbol : IntermediateSymbol
+    {
+        public HarvestPayloadsSymbol() : base(SymbolDefinitions.HarvestPayloads, null, null)
+        {
+        }
+
+        public HarvestPayloadsSymbol(SourceLineNumber sourceLineNumber, Identifier id = null) : base(SymbolDefinitions.HarvestPayloads, sourceLineNumber, id)
+        {
+        }
+
+        public IntermediateField this[HarvestPayloadsSymbolFields index] => this.Fields[(int)index];
+
+        public string Inclusions
+        {
+            get => (string)this.Fields[(int)HarvestPayloadsSymbolFields.Inclusions];
+            set => this.Set((int)HarvestPayloadsSymbolFields.Inclusions, value);
+        }
+
+        public string Exclusions
+        {
+            get => (string)this.Fields[(int)HarvestPayloadsSymbolFields.Exclusions];
+            set => this.Set((int)HarvestPayloadsSymbolFields.Exclusions, value);
+        }
+
+        public string ComplexReferenceParentType
+        {
+            get => (string)this.Fields[(int)HarvestPayloadsSymbolFields.ComplexReferenceParentType];
+            set => this.Set((int)HarvestPayloadsSymbolFields.ComplexReferenceParentType, value);
+        }
+
+        public string ParentId
+        {
+            get => (string)this.Fields[(int)HarvestPayloadsSymbolFields.ParentId];
+            set => this.Set((int)HarvestPayloadsSymbolFields.ParentId, value);
+        }
+    }
+}
diff --git a/src/api/wix/WixToolset.Data/Symbols/SymbolDefinitions.cs b/src/api/wix/WixToolset.Data/Symbols/SymbolDefinitions.cs
index 64f51162..64c1a2a5 100644
--- a/src/api/wix/WixToolset.Data/Symbols/SymbolDefinitions.cs
+++ b/src/api/wix/WixToolset.Data/Symbols/SymbolDefinitions.cs
@@ -41,6 +41,7 @@ namespace WixToolset.Data
         File,
         FileSFPCatalog,
         HarvestFiles,
+        HarvestPayloads,
         Icon,
         ImageFamilies,
         IniFile,
diff --git a/src/api/wix/WixToolset.Data/WarningMessages.cs b/src/api/wix/WixToolset.Data/WarningMessages.cs
index 15068a90..83d9dc51 100644
--- a/src/api/wix/WixToolset.Data/WarningMessages.cs
+++ b/src/api/wix/WixToolset.Data/WarningMessages.cs
@@ -357,11 +357,6 @@ namespace WixToolset.Data
             return Message(null, Ids.ImplicitMergeModulePrimaryFeature, "The merge module '{0}' does not have an explicit primary feature parent specified. If the source files are linked in a different order, the primary parent feature may change. To prevent accidental changes, the primary feature parent should be set to 'yes' in one of the MergeRef/@Primary or FeatureGroupRef/@Primary locations for this component.", componentId);
         }
 
-        public static Message InsufficientPermissionHarvestTypeLib()
-        {
-            return Message(null, Ids.InsufficientPermissionHarvestTypeLib, "Not enough permissions to harvest type library. On Windows Vista, you must either run Heat elevated, or install Windows Vista SP1 (or higher).");
-        }
-
         public static Message InvalidAttributeCombination(SourceLineNumber sourceLineNumbers, string attrib1, string attrib2, string name, string value)
         {
             return Message(sourceLineNumbers, Ids.InvalidAttributeCombination, "It is invalid to combine attributes {0} and {1}. The decompiled output will set attribute {2} to {3}.", attrib1, attrib2, name, value);
@@ -813,7 +808,6 @@ namespace WixToolset.Data
             UnexpectedEntrySection = 1109,
             NewComponentAddedToExistingFeature = 1110,
             DeprecatedAttributeValue = 1111,
-            InsufficientPermissionHarvestTypeLib = 1112,
             UnclearShortcut = 1113,
             TooManyProgIds = 1114,
             BadColumnDataIgnored = 1115,
diff --git a/src/api/wix/WixToolset.Data/WixToolset.Data.csproj b/src/api/wix/WixToolset.Data/WixToolset.Data.csproj
index e2d71e87..257b9415 100644
--- a/src/api/wix/WixToolset.Data/WixToolset.Data.csproj
+++ b/src/api/wix/WixToolset.Data/WixToolset.Data.csproj
@@ -6,8 +6,9 @@
     <TargetFrameworks>netstandard2.0</TargetFrameworks>
     <TargetFrameworks Condition=" '$(Configuration)'=='Release' ">$(TargetFrameworks);net472</TargetFrameworks>
     <LangVersion>7.3</LangVersion>
-    <Description>WiX Toolset Data</Description>
     <DebugType>embedded</DebugType>
+    <Description>WiX Toolset Data</Description>
+    <PackageReadmeFile>README.md</PackageReadmeFile>
     <PublishRepositoryUrl>true</PublishRepositoryUrl>
     <CreateDocumentationFile>true</CreateDocumentationFile>
     <!-- TODO: This shouldn't be ignored because this is public-facing -->
@@ -15,6 +16,10 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <None Include="README.md" Pack="true" PackagePath="\" />
+  </ItemGroup>
+
+  <ItemGroup>
     <PackageReference Include="System.IO.Compression" />
   </ItemGroup>
 </Project>
diff --git a/src/api/wix/WixToolset.Extensibility/README.md b/src/api/wix/WixToolset.Extensibility/README.md
new file mode 100644
index 00000000..62dee501
--- /dev/null
+++ b/src/api/wix/WixToolset.Extensibility/README.md
@@ -0,0 +1,30 @@
+# WixToolset.Extensibility - extensibility interfaces for the WiX Toolset
+
+The `WixToolset.Extensibility` package provides the interfaces and base classes WiX Extensions implement to extend the WiX Toolset.
+
+[Web Site][web] | [Documentation][docs] | [Issue Tracker][issues] | [Discussions][discussions]
+
+
+## Open Source Maintenance Fee
+
+To ensure the long-term sustainability of this project, users of this package who generate revenue must pay an [Open Source Maintenance Fee][osmf]. While the source code is freely available under the terms of the [LICENSE][license], this package and other aspects of the project require [adherence to the Open Source Maintenance Fee EULA][eula].
+
+To pay the Maintenance Fee, [become a Sponsor](https://github.com/sponsors/wixtoolset).
+
+
+## Additional resources
+
+* [WiX Website][web]
+* [WiX Documentation][docs]
+* [WiX Issue Tracker][issues]
+* [WiX Discussions][discussions]
+
+
+[web]: https://www.firegiant.com/wixtoolset/
+[docs]: https://docs.firegiant.com/wixtoolset/
+[issues]: https://github.com/wixtoolset/issues/issues
+[discussions]: https://github.com/orgs/wixtoolset/discussions
+[sdk]: https://www.nuget.org/packages/WixToolset.Sdk/
+[osmf]: https://opensourcemaintenancefee.org/
+[license]: https://github.com/wixtoolset/wix/blob/main/LICENSE.TXT
+[eula]: https://github.com/wixtoolset/wix/blob/main/OSMFEULA.txt
diff --git a/src/api/wix/WixToolset.Extensibility/WixToolset.Extensibility.csproj b/src/api/wix/WixToolset.Extensibility/WixToolset.Extensibility.csproj
index 86ee754d..f0938b6f 100644
--- a/src/api/wix/WixToolset.Extensibility/WixToolset.Extensibility.csproj
+++ b/src/api/wix/WixToolset.Extensibility/WixToolset.Extensibility.csproj
@@ -5,14 +5,18 @@
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0</TargetFrameworks>
     <TargetFrameworks Condition=" '$(Configuration)'=='Release' ">$(TargetFrameworks);net472</TargetFrameworks>
-    <Title>WiX Toolset Extensibility</Title>
-    <Description></Description>
     <DebugType>embedded</DebugType>
+    <Description>WiX Toolset Extensibility</Description>
+    <PackageReadmeFile>README.md</PackageReadmeFile>
     <PublishRepositoryUrl>true</PublishRepositoryUrl>
     <CreateDocumentationFile>true</CreateDocumentationFile>
   </PropertyGroup>
 
   <ItemGroup>
+    <None Include="README.md" Pack="true" PackagePath="\" />
+  </ItemGroup>
+
+  <ItemGroup>
     <ProjectReference Include="..\WixToolset.Data\WixToolset.Data.csproj" />
   </ItemGroup>
 </Project>