Move to .NET Core 2.0

35 files changed, 1745 insertions, 0 deletions

diff --git a/WixToolset.Extensibility.sln b/WixToolset.Extensibility.sln
new file mode 100644
index 00000000..94ce905c
--- /dev/null
+++ b/WixToolset.Extensibility.sln
@@ -0,0 +1,36 @@
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 15
+VisualStudioVersion = 15.0.26730.8
+MinimumVisualStudioVersion = 15.0.26124.0
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WixToolset.Extensibility", "src\WixToolset.Extensibility\WixToolset.Extensibility.csproj", "{AA049009-D7D9-4C63-8E0D-83206ADCFBD1}"
+EndProject
+Global
+        GlobalSection(SolutionConfigurationPlatforms) = preSolution
+                Debug|Any CPU = Debug|Any CPU
+                Debug|x64 = Debug|x64
+                Debug|x86 = Debug|x86
+                Release|Any CPU = Release|Any CPU
+                Release|x64 = Release|x64
+                Release|x86 = Release|x86
+        EndGlobalSection
+        GlobalSection(ProjectConfigurationPlatforms) = postSolution
+                {AA049009-D7D9-4C63-8E0D-83206ADCFBD1}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+                {AA049009-D7D9-4C63-8E0D-83206ADCFBD1}.Debug|Any CPU.Build.0 = Debug|Any CPU
+                {AA049009-D7D9-4C63-8E0D-83206ADCFBD1}.Debug|x64.ActiveCfg = Debug|Any CPU
+                {AA049009-D7D9-4C63-8E0D-83206ADCFBD1}.Debug|x64.Build.0 = Debug|Any CPU
+                {AA049009-D7D9-4C63-8E0D-83206ADCFBD1}.Debug|x86.ActiveCfg = Debug|Any CPU
+                {AA049009-D7D9-4C63-8E0D-83206ADCFBD1}.Debug|x86.Build.0 = Debug|Any CPU
+                {AA049009-D7D9-4C63-8E0D-83206ADCFBD1}.Release|Any CPU.ActiveCfg = Release|Any CPU
+                {AA049009-D7D9-4C63-8E0D-83206ADCFBD1}.Release|Any CPU.Build.0 = Release|Any CPU
+                {AA049009-D7D9-4C63-8E0D-83206ADCFBD1}.Release|x64.ActiveCfg = Release|Any CPU
+                {AA049009-D7D9-4C63-8E0D-83206ADCFBD1}.Release|x64.Build.0 = Release|Any CPU
+                {AA049009-D7D9-4C63-8E0D-83206ADCFBD1}.Release|x86.ActiveCfg = Release|Any CPU
+                {AA049009-D7D9-4C63-8E0D-83206ADCFBD1}.Release|x86.Build.0 = Release|Any CPU
+        EndGlobalSection
+        GlobalSection(SolutionProperties) = preSolution
+                HideSolutionNode = FALSE
+        EndGlobalSection
+        GlobalSection(ExtensibilityGlobals) = postSolution
+                SolutionGuid = {BB8820D5-723D-426D-B4A0-4D221603C5FA}
+        EndGlobalSection
+EndGlobal
diff --git a/src/Directory.Build.props b/src/Directory.Build.props
new file mode 100644
index 00000000..0ea54cfe
--- /dev/null
+++ b/src/Directory.Build.props
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+<Project>
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <BaseIntermediateOutputPath>$(MSBuildThisFileDirectory)..\build\obj\$(MSBuildProjectName)\</BaseIntermediateOutputPath>
+    <OutputPath>$(MSBuildThisFileDirectory)..\build\$(Configuration)\</OutputPath>
+
+    <Authors>Rob Mensching, Bob Arnson</Authors>
+    <Company>WiX Toolset</Company>
+    <Copyright>Copyright (c) .NET Foundation and contributors. All rights reserved.</Copyright>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <WixToolsetRootFolder>$(MSBuildThisFileDirectory)..\..\</WixToolsetRootFolder>
+  </PropertyGroup>
+</Project>
diff --git a/src/WixToolset.Extensibility/AssemblyInfo.cs b/src/WixToolset.Extensibility/AssemblyInfo.cs
new file mode 100644
index 00000000..6512230a
--- /dev/null
+++ b/src/WixToolset.Extensibility/AssemblyInfo.cs
@@ -0,0 +1,9 @@
+// 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.
+
+using System;
+using System.Reflection;
+using System.Runtime.InteropServices;
+
+[assembly: AssemblyCulture("")]
+[assembly:CLSCompliant(true)]
+[assembly: ComVisible(false)]
diff --git a/src/WixToolset.Extensibility/BindFileWithPath.cs b/src/WixToolset.Extensibility/BindFileWithPath.cs
new file mode 100644
index 00000000..f07873fc
--- /dev/null
+++ b/src/WixToolset.Extensibility/BindFileWithPath.cs
@@ -0,0 +1,20 @@
+// 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.Extensibility
+{
+    /// <summary>
+    /// Bind file with its path.
+    /// </summary>
+    public class BindFileWithPath
+    {
+        /// <summary>
+        /// Gets or sets the identifier of the file with this path.
+        /// </summary>
+        public string Id { get; set; }
+
+        /// <summary>
+        /// Gets or sets the file path.
+        /// </summary>
+        public string Path { get; set; }
+    }
+}
diff --git a/src/WixToolset.Extensibility/BindPath.cs b/src/WixToolset.Extensibility/BindPath.cs
new file mode 100644
index 00000000..236ee4ec
--- /dev/null
+++ b/src/WixToolset.Extensibility/BindPath.cs
@@ -0,0 +1,52 @@
+// 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.Extensibility
+{
+    using System;
+
+    /// <summary>
+    /// Bind path representation.
+    /// </summary>
+    public class BindPath
+    {
+        /// <summary>
+        /// Creates an unnamed bind path.
+        /// </summary>
+        /// <param name="path">Path for the bind path.</param>
+        public BindPath(string path) : this(String.Empty, path)
+        {
+        }
+
+        /// <summary>
+        /// Creates a named bind path.
+        /// </summary>
+        /// <param name="name">Name of the bind path.</param>
+        /// <param name="path">Path for the bind path.</param>
+        public BindPath(string name, string path)
+        {
+            this.Name = name;
+            this.Path = path;
+        }
+
+        /// <summary>
+        /// Parses a bind path from its string representation
+        /// </summary>
+        /// <param name="bindPath">String representation of bind path that looks like: [name=]path</param>
+        /// <returns>Parsed bind path.</returns>
+        public static BindPath Parse(string bindPath)
+        {
+            string[] namedPath = bindPath.Split(new char[] { '=' }, 2);
+            return (1 == namedPath.Length) ? new BindPath(namedPath[0]) : new BindPath(namedPath[0], namedPath[1]);
+        }
+
+        /// <summary>
+        /// Name of the bind path or String.Empty if the path is unnamed.
+        /// </summary>
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Path for the bind path.
+        /// </summary>
+        public string Path { get; set; }
+    }
+}
diff --git a/src/WixToolset.Extensibility/BindStage.cs b/src/WixToolset.Extensibility/BindStage.cs
new file mode 100644
index 00000000..71ac5616
--- /dev/null
+++ b/src/WixToolset.Extensibility/BindStage.cs
@@ -0,0 +1,27 @@
+// 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.Extensibility
+{
+    /// <summary>
+    /// Bind stage of a file.. The reason we need this is to change the ResolveFile behavior based on if
+    /// dynamic bindpath plugin is desirable. We cannot change the signature of ResolveFile since it might
+    /// break existing implementers which derived from BinderFileManager
+    /// </summary>
+    public enum BindStage
+    {
+        /// <summary>
+        /// Normal binding
+        /// </summary>
+        Normal,
+
+        /// <summary>
+        /// Bind the file path of the target build file
+        /// </summary>
+        Target,
+
+        /// <summary>
+        /// Bind the file path of the updated build file
+        /// </summary>
+        Updated,
+    }
+}
diff --git a/src/WixToolset.Extensibility/BinderExtension.cs b/src/WixToolset.Extensibility/BinderExtension.cs
new file mode 100644
index 00000000..c6ccb3c2
--- /dev/null
+++ b/src/WixToolset.Extensibility/BinderExtension.cs
@@ -0,0 +1,40 @@
+// 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.Extensibility
+{
+    using WixToolset.Data;
+
+    /// <summary>
+    /// Base class for creating an binder extension.
+    /// </summary>
+    public abstract class BinderExtension : IBinderExtension
+    {
+        /// <summary>
+        /// Gets or sets the binder core for the extension.
+        /// </summary>
+        /// <value>Binder core for the extension.</value>
+        public IBinderCore Core { get; set; }
+
+
+        /// <summary>
+        /// Called before binding occurs.
+        /// </summary>
+        public virtual void Initialize(Output output)
+        {
+        }
+
+        /// <summary>
+        /// Called after variable resolution occurs.
+        /// </summary>
+        public virtual void AfterResolvedFields(Output output)
+        {
+        }
+
+        /// <summary>
+        /// Called after all output changes occur and right before the output is bound into its final format.
+        /// </summary>
+        public virtual void Finish(Output output)
+        {
+        }
+    }
+}
diff --git a/src/WixToolset.Extensibility/CabinetBuildOption.cs b/src/WixToolset.Extensibility/CabinetBuildOption.cs
new file mode 100644
index 00000000..6f63131c
--- /dev/null
+++ b/src/WixToolset.Extensibility/CabinetBuildOption.cs
@@ -0,0 +1,25 @@
+// 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.Extensibility
+{
+    /// <summary>
+    /// Options for building the cabinet.
+    /// </summary>
+    public enum CabinetBuildOption
+    {
+        /// <summary>
+        /// Build the cabinet and move it to the target location.
+        /// </summary>
+        BuildAndMove,
+
+        /// <summary>
+        /// Build the cabinet and copy it to the target location.
+        /// </summary>
+        BuildAndCopy,
+
+        /// <summary>
+        /// Just copy the cabinet to the target location.
+        /// </summary>
+        Copy
+    }
+}
diff --git a/src/WixToolset.Extensibility/CompilerConstants.cs b/src/WixToolset.Extensibility/CompilerConstants.cs
new file mode 100644
index 00000000..6d4ca742
--- /dev/null
+++ b/src/WixToolset.Extensibility/CompilerConstants.cs
@@ -0,0 +1,19 @@
+// 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
+{
+    using System;
+
+    /// <summary>
+    /// Constants used by compiler.
+    /// </summary>
+    public class CompilerConstants
+    {
+        public const int IntegerNotSet = int.MinValue;
+        public const int IllegalInteger = int.MinValue + 1;
+        public const long LongNotSet = long.MinValue;
+        public const long IllegalLong = long.MinValue + 1;
+        public const string IllegalGuid = "IllegalGuid";
+        public static readonly Version IllegalVersion = new Version(Int32.MaxValue, Int32.MaxValue, Int32.MaxValue, Int32.MaxValue);
+    }
+}
diff --git a/src/WixToolset.Extensibility/CompilerExtension.cs b/src/WixToolset.Extensibility/CompilerExtension.cs
new file mode 100644
index 00000000..522ffcf8
--- /dev/null
+++ b/src/WixToolset.Extensibility/CompilerExtension.cs
@@ -0,0 +1,74 @@
+// 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.Extensibility
+{
+    using System.Collections.Generic;
+    using System.Xml.Linq;
+
+    /// <summary>
+    /// Base class for creating a compiler extension.
+    /// </summary>
+    public abstract class CompilerExtension : ICompilerExtension
+    {
+        /// <summary>
+        /// Gets or sets the compiler core for the extension.
+        /// </summary>
+        /// <value>Compiler core for the extension.</value>
+        public ICompilerCore Core { get; set; }
+
+        /// <summary>
+        /// Gets the schema namespace for this extension.
+        /// </summary>
+        /// <value>Schema namespace supported by this extension.</value>
+        public XNamespace Namespace { get; protected set; }
+
+        /// <summary>
+        /// Called at the beginning of the compilation of a source file.
+        /// </summary>
+        public virtual void Initialize()
+        {
+        }
+
+        /// <summary>
+        /// Processes an attribute for the Compiler.
+        /// </summary>
+        /// <param name="parentElement">Parent element of attribute.</param>
+        /// <param name="attribute">Attribute to process.</param>
+        /// <param name="context">Extra information about the context in which this element is being parsed.</param>
+        public virtual void ParseAttribute(XElement parentElement, XAttribute attribute, IDictionary<string, string> context)
+        {
+            this.Core.UnexpectedAttribute(parentElement, attribute);
+        }
+
+        /// <summary>
+        /// Processes an element for the Compiler.
+        /// </summary>
+        /// <param name="parentElement">Parent element of element to process.</param>
+        /// <param name="element">Element to process.</param>
+        /// <param name="contextValues">Extra information about the context in which this element is being parsed.</param>
+        public virtual void ParseElement(XElement parentElement, XElement element, IDictionary<string, string> context)
+        {
+            this.Core.UnexpectedElement(parentElement, element);
+        }
+
+        /// <summary>
+        /// Processes an element for the Compiler, with the ability to supply a component keypath.
+        /// </summary>
+        /// <param name="parentElement">Parent element of element to process.</param>
+        /// <param name="element">Element to process.</param>
+        /// <param name="keyPath">Explicit key path.</param>
+        /// <param name="contextValues">Extra information about the context in which this element is being parsed.</param>
+        public virtual ComponentKeyPath ParsePossibleKeyPathElement(XElement parentElement, XElement element, IDictionary<string, string> context)
+        {
+            this.ParseElement(parentElement, element, context);
+            return null;
+        }
+
+        /// <summary>
+        /// Called at the end of the compilation of a source file.
+        /// </summary>
+        public virtual void Finish()
+        {
+        }
+    }
+}
diff --git a/src/WixToolset.Extensibility/ComponentKeyPath.cs b/src/WixToolset.Extensibility/ComponentKeyPath.cs
new file mode 100644
index 00000000..f00e8f74
--- /dev/null
+++ b/src/WixToolset.Extensibility/ComponentKeyPath.cs
@@ -0,0 +1,57 @@
+// 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.Extensibility
+{
+    using System;
+
+    public enum ComponentKeyPathType
+    {
+        /// <summary>
+        /// Not a key path.
+        /// </summary>
+        None,
+
+        /// <summary>
+        /// File resource as a key path.
+        /// </summary>
+        File,
+
+        /// <summary>
+        /// Folder as a key path.
+        /// </summary>
+        Directory,
+
+        /// <summary>
+        /// ODBC data source as a key path.
+        /// </summary>
+        OdbcDataSource,
+
+        /// <summary>
+        /// A simple registry key acting as a key path.
+        /// </summary>
+        Registry,
+
+        /// <summary>
+        /// A registry key that contains a formatted property acting as a key path.
+        /// </summary>
+        RegistryFormatted
+    }
+
+    public class ComponentKeyPath
+    {
+        /// <summary>
+        /// Identifier of the resource to be a key path.
+        /// </summary>
+        public string Id { get; set; }
+
+        /// <summary>
+        /// Indicates whether the key path was explicitly set for this resource.
+        /// </summary>
+        public bool Explicit { get; set; }
+
+        /// <summary>
+        /// Type of resource to be the key path.
+        /// </summary>
+        public ComponentKeyPathType Type { get; set; }
+    }
+}
diff --git a/src/WixToolset.Extensibility/DecompilerConstants.cs b/src/WixToolset.Extensibility/DecompilerConstants.cs
new file mode 100644
index 00000000..58742182
--- /dev/null
+++ b/src/WixToolset.Extensibility/DecompilerConstants.cs
@@ -0,0 +1,15 @@
+// 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
+{
+    using System;
+
+    /// <summary>
+    /// Constants used by decompiler.
+    /// </summary>
+    public class DecompilerConstants
+    {
+        public const char PrimaryKeyDelimiter = '/';
+        public const string PrimaryKeyDelimiterString = "/";
+    }
+}
diff --git a/src/WixToolset.Extensibility/DecompilerExtension.cs b/src/WixToolset.Extensibility/DecompilerExtension.cs
new file mode 100644
index 00000000..00277639
--- /dev/null
+++ b/src/WixToolset.Extensibility/DecompilerExtension.cs
@@ -0,0 +1,59 @@
+// 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.Extensibility
+{
+    using WixToolset.Data;
+
+    /// <summary>
+    /// Base class for creating a decompiler extension.
+    /// </summary>
+    public abstract class DecompilerExtension : IDecompilerExtension
+    {
+        /// <summary>
+        /// Gets or sets the decompiler core for the extension.
+        /// </summary>
+        /// <value>The decompiler core for the extension.</value>
+        public IDecompilerCore Core { get; set; }
+
+        /// <summary>
+        /// Gets the table definitions this extension decompiles.
+        /// </summary>
+        /// <value>Table definitions this extension decompiles.</value>
+        public virtual TableDefinitionCollection TableDefinitions { get; protected set; }
+
+        /// <summary>
+        /// Gets the library that this decompiler wants removed from the decomipiled output.
+        /// </summary>
+        /// <param name="tableDefinitions">The table definitions to use while loading the library.</param>
+        /// <returns>The library for this extension or null if there is no library to be removed.</returns>
+        public virtual Library GetLibraryToRemove(TableDefinitionCollection tableDefinitions)
+        {
+            return null;
+        }
+
+        /// <summary>
+        /// Called at the beginning of the decompilation of a database.
+        /// </summary>
+        /// <param name="tables">The collection of all tables.</param>
+        public virtual void Initialize(TableIndexedCollection tables)
+        {
+        }
+
+        /// <summary>
+        /// Decompiles an extension table.
+        /// </summary>
+        /// <param name="table">The table to decompile.</param>
+        public virtual void DecompileTable(Table table)
+        {
+            this.Core.UnexpectedTable(table);
+        }
+
+        /// <summary>
+        /// Finalize decompilation.
+        /// </summary>
+        /// <param name="tables">The collection of all tables.</param>
+        public virtual void Finish(TableIndexedCollection tables)
+        {
+        }
+    }
+}
diff --git a/src/WixToolset.Extensibility/ExtensionData.cs b/src/WixToolset.Extensibility/ExtensionData.cs
new file mode 100644
index 00000000..4cf262b9
--- /dev/null
+++ b/src/WixToolset.Extensibility/ExtensionData.cs
@@ -0,0 +1,75 @@
+// 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.Extensibility
+{
+    using System;
+    using System.IO;
+    using System.Reflection;
+    using System.Xml;
+    using WixToolset.Data;
+
+    public abstract class ExtensionData : IExtensionData
+    {
+        /// <summary>
+        /// Gets the optional table definitions for this extension.
+        /// </summary>
+        /// <value>Table definisions for this extension or null if there are no table definitions.</value>
+        public virtual TableDefinitionCollection TableDefinitions
+        {
+            get { return null; }
+        }
+
+        /// <summary>
+        /// Gets the optional default culture.
+        /// </summary>
+        /// <value>The optional default culture.</value>
+        public virtual string DefaultCulture
+        {
+            get { return null; }
+        }
+
+        /// <summary>
+        /// Gets the optional library associated with this extension.
+        /// </summary>
+        /// <param name="tableDefinitions">The table definitions to use while loading the library.</param>
+        /// <returns>The library for this extension or null if there is no library.</returns>
+        public virtual Library GetLibrary(TableDefinitionCollection tableDefinitions)
+        {
+            return null;
+        }
+
+        /// <summary>
+        /// Help for loading a library from an embedded resource.
+        /// </summary>
+        /// <param name="assembly">The assembly containing the embedded resource.</param>
+        /// <param name="resourceName">The name of the embedded resource being requested.</param>
+        /// <param name="tableDefinitions">The table definitions to use while loading the library.</param>
+        /// <returns>The loaded library.</returns>
+        protected static Library LoadLibraryHelper(Assembly assembly, string resourceName, TableDefinitionCollection tableDefinitions)
+        {
+            using (Stream resourceStream = assembly.GetManifestResourceStream(resourceName))
+            {
+                UriBuilder uriBuilder = new UriBuilder(assembly.CodeBase);
+                uriBuilder.Scheme = "embeddedresource";
+                uriBuilder.Fragment = resourceName;
+
+                return Library.Load(resourceStream, uriBuilder.Uri, tableDefinitions, false);
+            }
+        }
+
+        /// <summary>
+        /// Helper for loading table definitions from an embedded resource.
+        /// </summary>
+        /// <param name="assembly">The assembly containing the embedded resource.</param>
+        /// <param name="resourceName">The name of the embedded resource being requested.</param>
+        /// <returns>The loaded table definitions.</returns>
+        protected static TableDefinitionCollection LoadTableDefinitionHelper(Assembly assembly, string resourceName)
+        {
+            using (Stream resourceStream = assembly.GetManifestResourceStream(resourceName))
+            using (XmlReader reader = XmlReader.Create(resourceStream))
+            {
+                return TableDefinitionCollection.Load(reader);
+            }
+        }
+    }
+}
diff --git a/src/WixToolset.Extensibility/ExtensionHelper.cs b/src/WixToolset.Extensibility/ExtensionHelper.cs
new file mode 100644
index 00000000..9c1ca950
--- /dev/null
+++ b/src/WixToolset.Extensibility/ExtensionHelper.cs
@@ -0,0 +1,53 @@
+// 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.Extensibility
+{
+    using System;
+    using System.Collections.Specialized;
+    using System.IO;
+    using System.Reflection;
+    using System.Xml;
+    using WixToolset.Data;
+    using WixToolset.Extensibility;
+
+    /// <summary>
+    /// The main class for a WiX extension.
+    /// </summary>
+    public static class ExtensionHelper
+    {
+        /// <summary>
+        /// Help for loading a library from an embedded resource.
+        /// </summary>
+        /// <param name="assembly">The assembly containing the embedded resource.</param>
+        /// <param name="resourceName">The name of the embedded resource being requested.</param>
+        /// <param name="tableDefinitions">The table definitions to use while loading the library.</param>
+        /// <returns>The loaded library.</returns>
+        public static Library LoadLibraryHelper(Assembly assembly, string resourceName, TableDefinitionCollection tableDefinitions)
+        {
+            using (Stream resourceStream = assembly.GetManifestResourceStream(resourceName))
+            {
+                UriBuilder uriBuilder = new UriBuilder();
+                uriBuilder.Scheme = "embeddedresource";
+                uriBuilder.Path = assembly.Location;
+                uriBuilder.Fragment = resourceName;
+
+                return Library.Load(resourceStream, uriBuilder.Uri, tableDefinitions, false);
+            }
+        }
+
+        /// <summary>
+        /// Helper for loading table definitions from an embedded resource.
+        /// </summary>
+        /// <param name="assembly">The assembly containing the embedded resource.</param>
+        /// <param name="resourceName">The name of the embedded resource being requested.</param>
+        /// <returns>The loaded table definitions.</returns>
+        public static TableDefinitionCollection LoadTableDefinitionHelper(Assembly assembly, string resourceName)
+        {
+            using (Stream resourceStream = assembly.GetManifestResourceStream(resourceName))
+            using (XmlReader reader = XmlReader.Create(resourceStream))
+            {
+                return TableDefinitionCollection.Load(reader);
+            }
+        }
+    }
+}
diff --git a/src/WixToolset.Extensibility/IBinderCore.cs b/src/WixToolset.Extensibility/IBinderCore.cs
new file mode 100644
index 00000000..a4044c11
--- /dev/null
+++ b/src/WixToolset.Extensibility/IBinderCore.cs
@@ -0,0 +1,35 @@
+// 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.Extensibility
+{
+    using WixToolset.Data;
+
+    public interface IBinderCore : IMessageHandler
+    {
+        /// <summary>
+        /// Gets or sets the file manager core for the extension.
+        /// </summary>
+        /// <value>File manager core for the extension.</value>
+        IBinderFileManagerCore FileManagerCore { get; set; }
+
+        /// <summary>
+        /// Gets whether the binder core encountered an error while processing.
+        /// </summary>
+        /// <value>Flag if core encountered an error during processing.</value>
+        bool EncounteredError { get; }
+
+        /// <summary>
+        /// Gets the table definitions used by the Binder.
+        /// </summary>
+        /// <value>Table definitions used by the binder.</value>
+        TableDefinitionCollection TableDefinitions { get; }
+
+        /// <summary>
+        /// Generate an identifier by hashing data from the row.
+        /// </summary>
+        /// <param name="prefix">Three letter or less prefix for generated row identifier.</param>
+        /// <param name="args">Information to hash.</param>
+        /// <returns>The generated identifier.</returns>
+        string CreateIdentifier(string prefix, params string[] args);
+    }
+}
diff --git a/src/WixToolset.Extensibility/IBinderExtension.cs b/src/WixToolset.Extensibility/IBinderExtension.cs
new file mode 100644
index 00000000..19790b14
--- /dev/null
+++ b/src/WixToolset.Extensibility/IBinderExtension.cs
@@ -0,0 +1,33 @@
+// 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.Extensibility
+{
+    using WixToolset.Data;
+
+    /// <summary>
+    /// Interface all binder extensions implement.
+    /// </summary>
+    public interface IBinderExtension
+    {
+        /// <summary>
+        /// Gets or sets the binder core for the extension.
+        /// </summary>
+        /// <value>Binder core for the extension.</value>
+        IBinderCore Core { get; set; }
+
+        /// <summary>
+        /// Called before binding occurs.
+        /// </summary>
+        void Initialize(Output output);
+
+        /// <summary>
+        /// Called after variable resolution occurs.
+        /// </summary>
+        void AfterResolvedFields(Output output);
+
+        /// <summary>
+        /// Called after all output changes occur and right before the output is bound into its final format.
+        /// </summary>
+        void Finish(Output output);
+    }
+}
diff --git a/src/WixToolset.Extensibility/IBinderFileManager.cs b/src/WixToolset.Extensibility/IBinderFileManager.cs
new file mode 100644
index 00000000..3a2b1d40
--- /dev/null
+++ b/src/WixToolset.Extensibility/IBinderFileManager.cs
@@ -0,0 +1,29 @@
+// 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.Extensibility
+{
+    using System.Collections.Generic;
+    using WixToolset.Data;
+    using WixToolset.Data.Rows;
+
+    public interface IBinderFileManager
+    {
+        IBinderFileManagerCore Core { set; }
+
+        ResolvedCabinet ResolveCabinet(string cabinetPath, IEnumerable<BindFileWithPath> files);
+
+        string ResolveFile(string source, string type, SourceLineNumber sourceLineNumbers, BindStage bindStage);
+
+        string ResolveRelatedFile(string source, string relatedSource, string type, SourceLineNumber sourceLineNumbers, BindStage bindStage);
+
+        string ResolveMedia(MediaRow mediaRow, string mediaLayoutDirectory, string layoutDirectory);
+
+        string ResolveUrl(string url, string fallbackUrl, string packageId, string payloadId, string fileName);
+
+        bool? CompareFiles(string targetFile, string updatedFile);
+
+        bool CopyFile(string source, string destination, bool overwrite);
+
+        bool MoveFile(string source, string destination, bool overwrite);
+    }
+}
diff --git a/src/WixToolset.Extensibility/IBinderFileManagerCore.cs b/src/WixToolset.Extensibility/IBinderFileManagerCore.cs
new file mode 100644
index 00000000..f5adf4e1
--- /dev/null
+++ b/src/WixToolset.Extensibility/IBinderFileManagerCore.cs
@@ -0,0 +1,54 @@
+// 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.Extensibility
+{
+    using System.Collections.Generic;
+    using WixToolset.Data;
+
+    public interface IBinderFileManagerCore : IMessageHandler
+    {
+        /// <summary>
+        /// Gets or sets the path to cabinet cache.
+        /// </summary>
+        /// <value>The path to cabinet cache.</value>
+        string CabCachePath { get; }
+
+        /// <summary>
+        /// Gets or sets the active subStorage used for binding.
+        /// </summary>
+        /// <value>The subStorage object.</value>
+        SubStorage ActiveSubStorage { get; }
+
+        /// <summary>
+        /// Gets or sets the output object used for binding.
+        /// </summary>
+        /// <value>The output object.</value>
+        Output Output { get; }
+
+        /// <summary>
+        /// Gets or sets the path to the temp files location.
+        /// </summary>
+        /// <value>The path to the temp files location.</value>
+        string TempFilesLocation { get; }
+
+        /// <summary>
+        /// Gets the property if re-basing target is true or false
+        /// </summary>
+        /// <value>It returns true if target bind path is to be replaced, otherwise false.</value>
+        bool RebaseTarget { get; }
+
+        /// <summary>
+        /// Gets the property if re-basing updated build is true or false
+        /// </summary>
+        /// <value>It returns true if updated bind path is to be replaced, otherwise false.</value>
+        bool RebaseUpdated { get; }
+
+        /// <summary>
+        /// Gets the collection of paths to locate files during ResolveFile for the provided BindStage and name.
+        /// </summary>
+        /// <param name="stage">Optional stage to get bind paths for. Default is normal.</param>
+        /// <param name="name">Optional name of the bind paths to get. Default is the unnamed paths.</param>
+        /// <value>The bind paths to locate files.</value>
+        IEnumerable<string> GetBindPaths(BindStage stage = BindStage.Normal, string name = null);
+    }
+}
diff --git a/src/WixToolset.Extensibility/ICompilerCore.cs b/src/WixToolset.Extensibility/ICompilerCore.cs
new file mode 100644
index 00000000..b2ad6abd
--- /dev/null
+++ b/src/WixToolset.Extensibility/ICompilerCore.cs
@@ -0,0 +1,339 @@
+// 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.Extensibility
+{
+    using System;
+    using System.Collections;
+    using System.Collections.Generic;
+    using System.Xml.Linq;
+    using WixToolset.Data;
+
+    /// <summary>
+    /// Core interface provided by the compiler.
+    /// </summary>
+    public interface ICompilerCore : IMessageHandler
+    {
+        /// <summary>
+        /// Gets whether the compiler core encountered an error while processing.
+        /// </summary>
+        /// <value>Flag if core encountered an error during processing.</value>
+        bool EncounteredError { get; }
+
+        /// <summary>
+        /// Gets the platform which the compiler will use when defaulting 64-bit attributes and elements.
+        /// </summary>
+        /// <value>The platform which the compiler will use when defaulting 64-bit attributes and elements.</value>
+        Platform CurrentPlatform { get; }
+
+        /// <summary>
+        /// Creates a version 3 name-based UUID.
+        /// </summary>
+        /// <param name="namespaceGuid">The namespace UUID.</param>
+        /// <param name="value">The value.</param>
+        /// <returns>The generated GUID for the given namespace and value.</returns>
+        string CreateGuid(Guid namespaceGuid, string value);
+
+        /// <summary>
+        /// Create an identifier by hashing data from the row.
+        /// </summary>
+        /// <param name="prefix">Three letter or less prefix for generated row identifier.</param>
+        /// <param name="args">Information to hash.</param>
+        /// <returns>The new identifier.</returns>
+        Identifier CreateIdentifier(string prefix, params string[] args);
+
+        /// <summary>
+        /// Create an identifier based on passed file name
+        /// </summary>
+        /// <param name="name">File name to generate identifer from</param>
+        /// <returns></returns>
+        Identifier CreateIdentifierFromFilename(string filename);
+
+        /// <summary>
+        /// Convert a bit array into an int value.
+        /// </summary>
+        /// <param name="bits">The bit array to convert.</param>
+        /// <returns>The converted int value.</returns>
+        int CreateIntegerFromBitArray(BitArray bits);
+
+        /// <summary>
+        /// Creates a row in the active section.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source and line number of current row.</param>
+        /// <param name="tableName">Name of table to create row in.</param>
+        /// <param name="identifier">Optional identifier for the row.</param>
+        /// <returns>New row.</returns>
+        Row CreateRow(SourceLineNumber sourceLineNumbers, string tableName, Identifier identifier = null);
+
+        /// <summary>
+        /// Creates directories using the inline directory syntax.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line information.</param>
+        /// <param name="attribute">The attribute to parse.</param>
+        /// <param name="parentId">Optional identifier of parent directory.</param>
+        /// <returns>Identifier of the leaf directory created.</returns>
+        string CreateDirectoryReferenceFromInlineSyntax(SourceLineNumber sourceLineNumbers, XAttribute attribute, string parentId);
+
+        /// <summary>
+        /// Creates a Registry row in the active section.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source and line number of the current row.</param>
+        /// <param name="root">The registry entry root.</param>
+        /// <param name="key">The registry entry key.</param>
+        /// <param name="name">The registry entry name.</param>
+        /// <param name="value">The registry entry value.</param>
+        /// <param name="componentId">The component which will control installation/uninstallation of the registry entry.</param>
+        /// <param name="escapeLeadingHash">If true, "escape" leading '#' characters so the value is written as a REG_SZ.</param>
+        Identifier CreateRegistryRow(SourceLineNumber sourceLineNumbers, int root, string key, string name, string value, string componentId, bool escapeLeadingHash = false);
+
+        /// <summary>
+        /// Creates a short file/directory name using an identifier and long file/directory name as input.
+        /// </summary>
+        /// <param name="longName">The long file/directory name.</param>
+        /// <param name="keepExtension">The option to keep the extension on generated short names.</param>
+        /// <param name="allowWildcards">true if wildcards are allowed in the filename.</param>
+        /// <param name="args">Any additional information to include in the hash for the generated short name.</param>
+        /// <returns>The generated 8.3-compliant short file/directory name.</returns>
+        string CreateShortName(string longName, bool keepExtension, bool allowWildcards, params string[] args);
+
+        /// <summary>
+        /// Create a WixSimpleReference row in the active section.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line information for the row.</param>
+        /// <param name="tableName">The table name of the simple reference.</param>
+        /// <param name="primaryKeys">The primary keys of the simple reference.</param>
+        void CreateSimpleReference(SourceLineNumber sourceLineNumbers, string tableName, params string[] primaryKeys);
+
+        /// <summary>
+        /// Creates WixComplexReference and WixGroup rows in the active section.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line information.</param>
+        /// <param name="parentType">The parent type.</param>
+        /// <param name="parentId">The parent id.</param>
+        /// <param name="parentLanguage">The parent language.</param>
+        /// <param name="childType">The child type.</param>
+        /// <param name="childId">The child id.</param>
+        /// <param name="isPrimary">Whether the child is primary.</param>
+        void CreateComplexReference(SourceLineNumber sourceLineNumbers, ComplexReferenceParentType parentType, string parentId, string parentLanguage, ComplexReferenceChildType childType, string childId, bool isPrimary);
+
+        /// <summary>
+        /// Creates a patch resource reference to the list of resoures to be filtered when producing a patch. This method should only be used when processing children of a patch family.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source and line number of current row.</param>
+        /// <param name="tableName">Name of table to create row in.</param>
+        /// <param name="primaryKeys">Array of keys that make up the primary key of the table.</param>
+        /// <returns>New row.</returns>
+        void CreatePatchFamilyChildReference(SourceLineNumber sourceLineNumbers, string tableName, params string[] primaryKeys);
+
+        /// <summary>
+        /// Checks if the string contains a property (i.e. "foo[Property]bar")
+        /// </summary>
+        /// <param name="possibleProperty">String to evaluate for properties.</param>
+        /// <returns>True if a property is found in the string.</returns>
+        bool ContainsProperty(string possibleProperty);
+
+        /// <summary>
+        /// Add the appropriate rows to make sure that the given table shows up in the resulting output.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line numbers.</param>
+        /// <param name="tableName">Name of the table to ensure existance of.</param>
+        void EnsureTable(SourceLineNumber sourceLineNumbers, string tableName);
+
+        /// <summary>
+        /// Get an attribute value and displays an error if the value is empty by default.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line information about the owner element.</param>
+        /// <param name="attribute">The attribute containing the value to get.</param>
+        /// <param name="emptyRule">A rule for the contents of the value. If the contents do not follow the rule, an error is thrown.</param>
+        /// <returns>The attribute's value.</returns>
+        string GetAttributeValue(SourceLineNumber sourceLineNumbers, XAttribute attribute, EmptyRule emptyRule = EmptyRule.CanBeWhitespaceOnly);
+
+        /// <summary>
+        /// Gets a Bundle variable value and displays an error for an illegal value.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line information about the owner element.</param>
+        /// <param name="attribute">The attribute containing the value to get.</param>
+        /// <returns>The attribute's value.</returns>
+        string GetAttributeBundleVariableValue(SourceLineNumber sourceLineNumbers, XAttribute attribute);
+
+        /// <summary>
+        /// Get a guid attribute value and displays an error for an illegal guid value.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line information about the owner element.</param>
+        /// <param name="attribute">The attribute containing the value to get.</param>
+        /// <param name="generatable">Determines whether the guid can be automatically generated.</param>
+        /// <param name="canBeEmpty">If true, no error is raised on empty value. If false, an error is raised.</param>
+        /// <returns>The attribute's guid value or a special value if an error occurred.</returns>
+        string GetAttributeGuidValue(SourceLineNumber sourceLineNumbers, XAttribute attribute, bool generatable = false, bool canBeEmpty = false);
+
+        /// <summary>
+        /// Get an identifier attribute value and displays an error for an illegal identifier value.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line information about the owner element.</param>
+        /// <param name="attribute">The attribute containing the value to get.</param>
+        /// <returns>The attribute's identifier value or a special value if an error occurred.</returns>
+        Identifier GetAttributeIdentifier(SourceLineNumber sourceLineNumbers, XAttribute attribute);
+
+        /// <summary>
+        /// Get an identifier attribute value and displays an error for an illegal identifier value.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line information about the owner element.</param>
+        /// <param name="attribute">The attribute containing the value to get.</param>
+        /// <returns>The attribute's identifier value or a special value if an error occurred.</returns>
+        string GetAttributeIdentifierValue(SourceLineNumber sourceLineNumbers, XAttribute attribute);
+
+        /// <summary>
+        /// Get an integer attribute value and displays an error for an illegal integer value.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line information about the owner element.</param>
+        /// <param name="attribute">The attribute containing the value to get.</param>
+        /// <param name="minimum">The minimum legal value.</param>
+        /// <param name="maximum">The maximum legal value.</param>
+        /// <returns>The attribute's integer value or a special value if an error occurred during conversion.</returns>
+        int GetAttributeIntegerValue(SourceLineNumber sourceLineNumbers, XAttribute attribute, int minimum, int maximum);
+
+        /// <summary>
+        /// Get a long integral attribute value and displays an error for an illegal long value.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line information about the owner element.</param>
+        /// <param name="attribute">The attribute containing the value to get.</param>
+        /// <param name="minimum">The minimum legal value.</param>
+        /// <param name="maximum">The maximum legal value.</param>
+        /// <returns>The attribute's long value or a special value if an error occurred during conversion.</returns>
+        long GetAttributeLongValue(SourceLineNumber sourceLineNumbers, XAttribute attribute, long minimum, long maximum);
+
+        /// <summary>
+        /// Gets a long filename value and displays an error for an illegal long filename value.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line information about the owner element.</param>
+        /// <param name="attribute">The attribute containing the value to get.</param>
+        /// <param name="allowWildcards">true if wildcards are allowed in the filename.</param>
+        /// <param name="allowRelative">true if relative paths are allowed in the filename.</param>
+        /// <returns>The attribute's long filename value.</returns>
+        string GetAttributeLongFilename(SourceLineNumber sourceLineNumbers, XAttribute attribute, bool allowWildcards = false, bool allowRelative = false);
+
+        /// <summary>
+        /// Gets a RegistryRoot as a MsiInterop.MsidbRegistryRoot value and displays an error for an illegal value.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line information about the owner element.</param>
+        /// <param name="attribute">The attribute containing the value to get.</param>
+        /// <param name="allowHkmu">Whether HKMU is returned as -1 (true), or treated as an error (false).</param>
+        /// <returns>The attribute's RegisitryRootType value.</returns>
+        int GetAttributeMsidbRegistryRootValue(SourceLineNumber sourceLineNumbers, XAttribute attribute, bool allowHkmu);
+
+        /// <summary>
+        /// Gets a version value or possibly a binder variable and displays an error for an illegal version value.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line information about the owner element.</param>
+        /// <param name="attribute">The attribute containing the value to get.</param>
+        /// <returns>The attribute's version value.</returns>
+        string GetAttributeVersionValue(SourceLineNumber sourceLineNumbers, XAttribute attribute);
+
+        /// <summary>
+        /// Gets a yes/no value and displays an error for an illegal yes/no value.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line information about the owner element.</param>
+        /// <param name="attribute">The attribute containing the value to get.</param>
+        /// <returns>The attribute's YesNoType value.</returns>
+        YesNoType GetAttributeYesNoValue(SourceLineNumber sourceLineNumbers, XAttribute attribute);
+
+        /// <summary>
+        /// Gets a yes/no/default value and displays an error for an illegal yes/no/default value.
+        /// </summary>
+        /// <param name="sourceLineNumbers">Source line information about the owner element.</param>
+        /// <param name="attribute">The attribute containing the value to get.</param>
+        /// <returns>The attribute's YesNoType value.</returns>
+        YesNoDefaultType GetAttributeYesNoDefaultValue(SourceLineNumber sourceLineNumbers, XAttribute attribute);
+
+        /// <summary>
+        /// Gets node's inner text and ensure's it is safe for use in a condition by trimming any extra whitespace.
+        /// </summary>
+        /// <param name="node">The node to ensure inner text is a condition.</param>
+        /// <returns>The value converted into a safe condition.</returns>
+        string GetConditionInnerText(XElement node);
+
+        /// <summary>
+        /// Get an element's inner text and trims any extra whitespace.
+        /// </summary>
+        /// <param name="element">The element with inner text to be trimmed.</param>
+        /// <returns>The node's inner text trimmed.</returns>
+        string GetTrimmedInnerText(XElement element);
+
+        /// <summary>
+        /// Verifies that a value is a legal identifier.
+        /// </summary>
+        /// <param name="value">The value to verify.</param>
+        /// <returns>true if the value is an identifier; false otherwise.</returns>
+        bool IsValidIdentifier(string value);
+
+        /// <summary>
+        /// Verifies if an identifier is a valid loc identifier.
+        /// </summary>
+        /// <param name="identifier">Identifier to verify.</param>
+        /// <returns>True if the identifier is a valid loc identifier.</returns>
+        bool IsValidLocIdentifier(string identifier);
+
+        /// <summary>
+        /// Verifies if a filename is a valid long filename.
+        /// </summary>
+        /// <param name="filename">Filename to verify.</param>
+        /// <param name="allowWildcards">true if wildcards are allowed in the filename.</param>
+        /// <param name="allowRelative">true if relative paths are allowed in the filename.</param>
+        /// <returns>True if the filename is a valid long filename</returns>
+        bool IsValidLongFilename(string filename, bool allowWildcards = false, bool allowRelative = false);
+
+        /// <summary>
+        /// Verifies if a filename is a valid short filename.
+        /// </summary>
+        /// <param name="filename">Filename to verify.</param>
+        /// <param name="allowWildcards">true if wildcards are allowed in the filename.</param>
+        /// <returns>True if the filename is a valid short filename</returns>
+        bool IsValidShortFilename(string filename, bool allowWildcards = false);
+
+        /// <summary>
+        /// Attempts to use an extension to parse the attribute.
+        /// </summary>
+        /// <param name="element">Element containing attribute to be parsed.</param>
+        /// <param name="attribute">Attribute to be parsed.</param>
+        /// <param name="context">Extra information about the context in which this element is being parsed.</param>
+        void ParseExtensionAttribute(XElement element, XAttribute attribute, IDictionary<string, string> context = null);
+
+        /// <summary>
+        /// Attempts to use an extension to parse the element.
+        /// </summary>
+        /// <param name="parentElement">Element containing element to be parsed.</param>
+        /// <param name="element">Element to be parsed.</param>
+        /// <param name="contextValues">Extra information about the context in which this element is being parsed.</param>
+        void ParseExtensionElement(XElement parentElement, XElement element, IDictionary<string, string> context = null);
+
+        /// <summary>
+        /// Process all children of the element looking for extensions and erroring on the unexpected.
+        /// </summary>
+        /// <param name="element">Element to parse children.</param>
+        void ParseForExtensionElements(XElement element);
+
+        /// <summary>
+        /// Sets a bit in a bit array based on the index at which an attribute name was found in a string array.
+        /// </summary>
+        /// <param name="attributeNames">Array of attributes that map to bits.</param>
+        /// <param name="attributeName">Name of attribute to check.</param>
+        /// <param name="attributeValue">Value of attribute to check.</param>
+        /// <param name="bits">The bit array in which the bit will be set if found.</param>
+        /// <param name="offset">The offset into the bit array.</param>
+        /// <returns>true if the bit was set; false otherwise.</returns>
+        bool TrySetBitFromName(string[] attributeNames, string attributeName, YesNoType attributeValue, BitArray bits, int offset);
+
+        /// <summary>
+        /// Called when the compiler encounters an unexpected attribute.
+        /// </summary>
+        /// <param name="parentElement">Parent element that found unexpected attribute.</param>
+        /// <param name="attribute">Unexpected attribute.</param>
+        void UnexpectedAttribute(XElement element, XAttribute attribute);
+
+        /// <summary>
+        /// Called when the compiler encounters an unexpected child element.
+        /// </summary>
+        /// <param name="parentElement">Parent element that found unexpected child.</param>
+        /// <param name="childElement">Unexpected child element.</param>
+        void UnexpectedElement(XElement parentElement, XElement childElement);
+    }
+}
diff --git a/src/WixToolset.Extensibility/ICompilerExtension.cs b/src/WixToolset.Extensibility/ICompilerExtension.cs
new file mode 100644
index 00000000..edd7aa15
--- /dev/null
+++ b/src/WixToolset.Extensibility/ICompilerExtension.cs
@@ -0,0 +1,59 @@
+// 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.Extensibility
+{
+    using System.Collections.Generic;
+    using System.Xml.Linq;
+
+    /// <summary>
+    /// Interface all compiler extensions implement.
+    /// </summary>
+    public interface ICompilerExtension
+    {
+        /// <summary>
+        /// Gets or sets the compiler core for the extension.
+        /// </summary>
+        /// <value>Compiler core for the extension.</value>
+        ICompilerCore Core { get; set; }
+
+        /// <summary>
+        /// Gets the schema namespace for this extension.
+        /// </summary>
+        /// <value>Schema namespace supported by this extension.</value>
+        XNamespace Namespace { get; }
+
+        /// <summary>
+        /// Called at the beginning of the compilation of a source file.
+        /// </summary>
+        void Initialize();
+
+        /// <summary>
+        /// Processes an attribute for the Compiler.
+        /// </summary>
+        /// <param name="parentElement">Parent element of attribute.</param>
+        /// <param name="attribute">Attribute to process.</param>
+        /// <param name="context">Extra information about the context in which this element is being parsed.</param>
+        void ParseAttribute(XElement parentElement, XAttribute attribute, IDictionary<string, string> context);
+
+        /// <summary>
+        /// Processes an element for the Compiler.
+        /// </summary>
+        /// <param name="parentElement">Parent element of element to process.</param>
+        /// <param name="element">Element to process.</param>
+        /// <param name="context">Extra information about the context in which this element is being parsed.</param>
+        void ParseElement(XElement parentElement, XElement element, IDictionary<string, string> context);
+
+        /// <summary>
+        /// Processes an element for the Compiler, with the ability to supply a component keypath.
+        /// </summary>
+        /// <param name="parentElement">Parent element of element to process.</param>
+        /// <param name="element">Element to process.</param>
+        /// <param name="contextValues">Extra information about the context in which this element is being parsed.</param>
+        ComponentKeyPath ParsePossibleKeyPathElement(XElement parentElement, XElement element, IDictionary<string, string> context);
+
+        /// <summary>
+        /// Called at the end of the compilation of a source file.
+        /// </summary>
+        void Finish();
+    }
+}
diff --git a/src/WixToolset.Extensibility/IDecompilerCore.cs b/src/WixToolset.Extensibility/IDecompilerCore.cs
new file mode 100644
index 00000000..d18d5170
--- /dev/null
+++ b/src/WixToolset.Extensibility/IDecompilerCore.cs
@@ -0,0 +1,73 @@
+// 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.Extensibility
+{
+    using System;
+    using WixToolset.Data;
+    using Wix = WixToolset.Data.Serialize;
+
+    public interface IDecompilerCore : IMessageHandler
+    {
+
+        /// <summary>
+        /// Gets whether the decompiler core encountered an error while processing.
+        /// </summary>
+        /// <value>Flag if core encountered an error during processing.</value>
+        bool EncounteredError { get; }
+
+        /// <summary>
+        /// Gets the root element of the decompiled output.
+        /// </summary>
+        /// <value>The root element of the decompiled output.</value>
+        Wix.IParentElement RootElement { get; }
+
+        /// <summary>
+        /// Gets the UI element.
+        /// </summary>
+        /// <value>The UI element.</value>
+        Wix.UI UIElement { get; }
+
+        /// <summary>
+        /// Verifies if a filename is a valid short filename.
+        /// </summary>
+        /// <param name="filename">Filename to verify.</param>
+        /// <param name="allowWildcards">true if wildcards are allowed in the filename.</param>
+        /// <returns>True if the filename is a valid short filename</returns>
+        bool IsValidShortFilename(string filename, bool allowWildcards);
+
+        /// <summary>
+        /// Convert an Int32 into a DateTime.
+        /// </summary>
+        /// <param name="value">The Int32 value.</param>
+        /// <returns>The DateTime.</returns>
+        DateTime ConvertIntegerToDateTime(int value);
+
+        /// <summary>
+        /// Gets the element corresponding to the row it came from.
+        /// </summary>
+        /// <param name="row">The row corresponding to the element.</param>
+        /// <returns>The indexed element.</returns>
+        Wix.ISchemaElement GetIndexedElement(Row row);
+
+        /// <summary>
+        /// Gets the element corresponding to the primary key of the given table.
+        /// </summary>
+        /// <param name="table">The table corresponding to the element.</param>
+        /// <param name="primaryKey">The primary key corresponding to the element.</param>
+        /// <returns>The indexed element.</returns>
+        Wix.ISchemaElement GetIndexedElement(string table, params string[] primaryKey);
+
+        /// <summary>
+        /// Index an element by its corresponding row.
+        /// </summary>
+        /// <param name="row">The row corresponding to the element.</param>
+        /// <param name="element">The element to index.</param>
+        void IndexElement(Row row, Wix.ISchemaElement element);
+
+            /// <summary>
+        /// Indicates the decompiler encountered and unexpected table to decompile.
+        /// </summary>
+        /// <param name="table">Unknown decompiled table.</param>
+        void UnexpectedTable(Table table);
+}
+}
diff --git a/src/WixToolset.Extensibility/IDecompilerExtension.cs b/src/WixToolset.Extensibility/IDecompilerExtension.cs
new file mode 100644
index 00000000..6124f348
--- /dev/null
+++ b/src/WixToolset.Extensibility/IDecompilerExtension.cs
@@ -0,0 +1,49 @@
+// 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.Extensibility
+{
+    using WixToolset.Data;
+
+    /// <summary>
+    /// Base class for creating a decompiler extension.
+    /// </summary>
+    public interface IDecompilerExtension
+    {
+        /// <summary>
+        /// Gets or sets the decompiler core for the extension.
+        /// </summary>
+        /// <value>The decompiler core for the extension.</value>
+        IDecompilerCore Core { get; set; }
+
+        /// <summary>
+        /// Gets the table definitions this extension decompiles.
+        /// </summary>
+        /// <value>Table definitions this extension decompiles.</value>
+        TableDefinitionCollection TableDefinitions { get; }
+
+        /// <summary>
+        /// Gets the library that this decompiler wants removed from the decomipiled output.
+        /// </summary>
+        /// <param name="tableDefinitions">The table definitions to use while loading the library.</param>
+        /// <returns>The library for this extension or null if there is no library to be removed.</returns>
+        Library GetLibraryToRemove(TableDefinitionCollection tableDefinitions);
+
+        /// <summary>
+        /// Called at the beginning of the decompilation of a database.
+        /// </summary>
+        /// <param name="tables">The collection of all tables.</param>
+        void Initialize(TableIndexedCollection tables);
+
+        /// <summary>
+        /// Decompiles an extension table.
+        /// </summary>
+        /// <param name="table">The table to decompile.</param>
+        void DecompileTable(Table table);
+
+        /// <summary>
+        /// Finalize decompilation.
+        /// </summary>
+        /// <param name="tables">The collection of all tables.</param>
+        void Finish(TableIndexedCollection tables);
+    }
+}
diff --git a/src/WixToolset.Extensibility/IExtensionCommandLine.cs b/src/WixToolset.Extensibility/IExtensionCommandLine.cs
new file mode 100644
index 00000000..b6cff5d0
--- /dev/null
+++ b/src/WixToolset.Extensibility/IExtensionCommandLine.cs
@@ -0,0 +1,42 @@
+// 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.Extensibility
+{
+    using System.Collections.Generic;
+    using WixToolset.Data;
+
+    /// <summary>
+    /// A command line option.
+    /// </summary>
+    public struct ExtensionCommandLineSwitch
+    {
+        public string Switch { get; set; }
+
+        public string Description { get; set; }
+    }
+
+    /// <summary>
+    /// Interface extensions implement to be able to parse command-line options.
+    /// </summary>
+    public interface IExtensionCommandLine
+    {
+        /// <summary>
+        /// Sets the message handler for the extension.
+        /// </summary>
+        /// <value>Message handler for the extension.</value>
+        IMessageHandler MessageHandler { set; }
+
+        /// <summary>
+        /// Gets the supported command line types for this extension.
+        /// </summary>
+        /// <value>The supported command line types for this extension.</value>
+        IEnumerable<ExtensionCommandLineSwitch> CommandLineSwitches { get; }
+
+        /// <summary>
+        /// Parse the commandline arguments.
+        /// </summary>
+        /// <param name="args">Commandline arguments.</param>
+        /// <returns>Unparsed commandline arguments.</returns>
+        string[] ParseCommandLine(string[] args);
+    }
+}
diff --git a/src/WixToolset.Extensibility/IExtensionData.cs b/src/WixToolset.Extensibility/IExtensionData.cs
new file mode 100644
index 00000000..19e23590
--- /dev/null
+++ b/src/WixToolset.Extensibility/IExtensionData.cs
@@ -0,0 +1,31 @@
+// 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.Extensibility
+{
+    using WixToolset.Data;
+
+    /// <summary>
+    /// Interface extensions implement to provide data.
+    /// </summary>
+    public interface IExtensionData
+    {
+        /// <summary>
+        /// Gets the table definitions for this extension.
+        /// </summary>
+        /// <value>Table definisions for this extension or null if there are no table definitions.</value>
+        TableDefinitionCollection TableDefinitions { get; }
+
+        /// <summary>
+        /// Gets the optional default culture.
+        /// </summary>
+        /// <value>The optional default culture.</value>
+        string DefaultCulture { get; }
+
+        /// <summary>
+        /// Gets the library associated with this extension.
+        /// </summary>
+        /// <param name="tableDefinitions">The table definitions to use while loading the library.</param>
+        /// <returns>The library for this extension or null if there is no library.</returns>
+        Library GetLibrary(TableDefinitionCollection tableDefinitions);
+    }
+}
diff --git a/src/WixToolset.Extensibility/IInspectorCore.cs b/src/WixToolset.Extensibility/IInspectorCore.cs
new file mode 100644
index 00000000..06239ce5
--- /dev/null
+++ b/src/WixToolset.Extensibility/IInspectorCore.cs
@@ -0,0 +1,17 @@
+// 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.Extensibility
+{
+    using WixToolset.Data;
+
+    /// <summary>
+    /// Core facilities for inspector extensions.
+    /// </summary>
+    public interface IInspectorCore : IMessageHandler
+    {
+        /// <summary>
+        /// Gets whether an error occured.
+        /// </summary>
+        bool EncounteredError { get; }
+    }
+}
diff --git a/src/WixToolset.Extensibility/IInspectorExtension.cs b/src/WixToolset.Extensibility/IInspectorExtension.cs
new file mode 100644
index 00000000..b2a098b7
--- /dev/null
+++ b/src/WixToolset.Extensibility/IInspectorExtension.cs
@@ -0,0 +1,59 @@
+// 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.Extensibility
+{
+    using System;
+    using System.IO;
+    using WixToolset.Data;
+
+    /// <summary>
+    /// Interface for inspector extensions.
+    /// </summary>
+    /// <remarks>
+    /// The inspector methods are stateless, but extensions are loaded and last for the lifetime of the
+    /// containing classes like <see cref="Preprocessor"/>, <see cref="Compiler"/>, <see cref="Linker"/>,
+    /// <see cref="Differ"/>, and <see cref="Binder"/>. If you want to maintain state, you should check
+    /// if your data is loaded for each method and, if not, load it.
+    /// </remarks>
+    public interface IInspectorExtension
+    {
+        /// <summary>
+        /// Gets or sets the <see cref="InspectorCore"/> for inspector extensions to use.
+        /// </summary>
+        IInspectorCore Core { get; set; }
+
+        /// <summary>
+        /// Inspect the source before preprocessing.
+        /// </summary>
+        /// <param name="source">The source to preprocess.</param>
+        void InspectSource(Stream source);
+
+        /// <summary>
+        /// Inspect the compiled output.
+        /// </summary>
+        /// <param name="intermediate">The compiled output.</param>
+        void InspectIntermediate(Intermediate intermediate);
+
+        /// <summary>
+        /// Inspect the output.
+        /// </summary>
+        /// <param name="output">The output. May be called after linking or binding.</param>
+        /// <remarks>
+        /// To inspect a patch's filtered transforms, enumerate <see cref="Output.SubStorages"/>.
+        /// Transforms where the <see cref="SubStorage.Name"/> begins with "#" are
+        /// called patch transforms and instruct Windows Installer how to apply the
+        /// authored transforms - those that do not begin with "#". The authored
+        /// transforms are the primary transforms you'll typically want to inspect
+        /// and contain your changes to target products.
+        /// </remarks>
+        void InspectOutput(Output output);
+
+        /// <summary>
+        /// Inspect the final output after binding.
+        /// </summary>
+        /// <param name="filePath">The file path to the final bound output.</param>
+        /// <param name="pdb">The <see cref="Pdb"/> that contains source line numbers
+        /// for the database and all rows.</param>
+        void InspectDatabase(string filePath, Pdb pdb);
+    }
+}
diff --git a/src/WixToolset.Extensibility/IPreprocessorCore.cs b/src/WixToolset.Extensibility/IPreprocessorCore.cs
new file mode 100644
index 00000000..a0449139
--- /dev/null
+++ b/src/WixToolset.Extensibility/IPreprocessorCore.cs
@@ -0,0 +1,21 @@
+// 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.Extensibility
+{
+    using WixToolset.Data;
+
+    public interface IPreprocessorCore : IMessageHandler
+    {
+        /// <summary>
+        /// Gets or sets the platform which the compiler will use when defaulting 64-bit attributes and elements.
+        /// </summary>
+        /// <value>The platform which the compiler will use when defaulting 64-bit attributes and elements.</value>
+        Platform CurrentPlatform { get; }
+
+        /// <summary>
+        /// Gets whether the core encountered an error while processing.
+        /// </summary>
+        /// <value>Flag if core encountered an error during processing.</value>
+        bool EncounteredError { get; }
+    }
+}
diff --git a/src/WixToolset.Extensibility/IPreprocessorExtension.cs b/src/WixToolset.Extensibility/IPreprocessorExtension.cs
new file mode 100644
index 00000000..de415526
--- /dev/null
+++ b/src/WixToolset.Extensibility/IPreprocessorExtension.cs
@@ -0,0 +1,79 @@
+// 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.Extensibility
+{
+    using System;
+    using System.Xml.Linq;
+    using WixToolset.Data;
+
+    /// <summary>
+    /// Interface for extending the WiX toolset preprocessor.
+    /// </summary>
+    public interface IPreprocessorExtension
+    {
+        /// <summary>
+        /// Gets or sets the preprocessor core for the extension.
+        /// </summary>
+        /// <value>Preprocessor core for the extension.</value>
+        IPreprocessorCore Core { get; set; }
+
+        /// <summary>
+        /// Gets the variable prefixes for the extension.
+        /// </summary>
+        /// <value>The variable prefixes for the extension.</value>
+        string[] Prefixes { get; }
+
+        /// <summary>
+        /// Called at the beginning of the preprocessing of a source file.
+        /// </summary>
+        void Initialize();
+
+        /// <summary>
+        /// Gets the value of a variable whose prefix matches the extension.
+        /// </summary>
+        /// <param name="prefix">The prefix of the variable to be processed by the extension.</param>
+        /// <param name="name">The name of the variable.</param>
+        /// <returns>The value of the variable or null if the variable is undefined.</returns>
+        string GetVariableValue(string prefix, string name);
+
+        /// <summary>
+        /// Evaluates a function defined in the extension.
+        /// </summary>
+        /// <param name="prefix">The prefix of the function to be processed by the extension.</param>
+        /// <param name="function">The name of the function.</param>
+        /// <param name="args">The list of arguments.</param>
+        /// <returns>The value of the function or null if the function is not defined.</returns>
+        string EvaluateFunction(string prefix, string function, string[] args);
+
+        /// <summary>
+        /// Processes a pragma defined in the extension.
+        /// </summary>
+        /// <param name="sourceLineNumbers">The location of this pragma's PI.</param>
+        /// <param name="prefix">The prefix of the pragma to be processed by the extension.</param>
+        /// <param name="pragma">The name of the pragma.</param>
+        /// <param name="args">The pragma's arguments.</param>
+        /// <param name="parent">The parent node of the pragma.</param>
+        /// <returns>false if the pragma is not defined.</returns>
+        /// <comments>Don't return false for any condition except for unrecognized pragmas. Use Core.OnMessage for errors, warnings and messages.</comments>
+        bool ProcessPragma(SourceLineNumber sourceLineNumbers, string prefix, string pragma, string args, XContainer parent);
+
+        /// <summary>
+        /// Preprocess a document after normal preprocessing has completed.
+        /// </summary>
+        /// <param name="document">The document to preprocess.</param>
+        void PreprocessDocument(XDocument document);
+
+        /// <summary>
+        /// Preprocesses a parameter.
+        /// </summary>
+        /// <param name="name">Name of parameter that matches extension.</param>
+        /// <returns>The value of the parameter after processing.</returns>
+        /// <remarks>By default this method will cause an error if its called.</remarks>
+        string PreprocessParameter(string name);
+
+        /// <summary>
+        /// Called at the end of the preprocessing of a source file.
+        /// </summary>
+        void Finish();
+    }
+}
diff --git a/src/WixToolset.Extensibility/IUnbinderExtension.cs b/src/WixToolset.Extensibility/IUnbinderExtension.cs
new file mode 100644
index 00000000..88bf20d9
--- /dev/null
+++ b/src/WixToolset.Extensibility/IUnbinderExtension.cs
@@ -0,0 +1,18 @@
+// 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.Extensibility
+{
+    using System;
+    using WixToolset.Data;
+
+    /// <summary>
+    /// Base class for creating an unbinder extension.
+    /// </summary>
+    public interface IUnbinderExtension
+    {
+        /// <summary>
+        /// Called during the generation of sectionIds for an admin image.
+        /// </summary>
+        void GenerateSectionIds(Output output);
+    }
+}
diff --git a/src/WixToolset.Extensibility/Identifier.cs b/src/WixToolset.Extensibility/Identifier.cs
new file mode 100644
index 00000000..628cd335
--- /dev/null
+++ b/src/WixToolset.Extensibility/Identifier.cs
@@ -0,0 +1,31 @@
+// 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.Extensibility
+{
+    using System;
+    using WixToolset.Data;
+
+    /// <summary>
+    /// Class to define the identifier and access for a row.
+    /// </summary>
+    public class Identifier
+    {
+        public static Identifier Invalid = new Identifier(null, AccessModifier.Private);
+
+        public Identifier(string id, AccessModifier access)
+        {
+            this.Id = id;
+            this.Access = access;
+        }
+
+        /// <summary>
+        /// Access modifier for a row.
+        /// </summary>
+        public AccessModifier Access { get; private set; }
+
+        /// <summary>
+        /// Identifier for the row.
+        /// </summary>
+        public string Id { get; private set; }
+    }
+}
diff --git a/src/WixToolset.Extensibility/InspectorExtension.cs b/src/WixToolset.Extensibility/InspectorExtension.cs
new file mode 100644
index 00000000..82b1ef02
--- /dev/null
+++ b/src/WixToolset.Extensibility/InspectorExtension.cs
@@ -0,0 +1,61 @@
+// 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.Extensibility
+{
+    using System;
+    using System.IO;
+    using WixToolset.Data;
+
+    /// <summary>
+    /// Opitonal base class for inspector extensions.
+    /// </summary>
+    public class InspectorExtension : IInspectorExtension
+    {
+        /// <summary>
+        /// Gets the <see cref="InspectorCore"/> for inspector extensions to use.
+        /// </summary>
+        public IInspectorCore Core { get; set; }
+
+        /// <summary>
+        /// Inspect the source before preprocessing.
+        /// </summary>
+        /// <param name="source">The source to preprocess.</param>
+        public virtual void InspectSource(Stream source)
+        {
+        }
+
+        /// <summary>
+        /// Inspect the compiled output.
+        /// </summary>
+        /// <param name="intermediate">The compiled output.</param>
+        public virtual void InspectIntermediate(Intermediate intermediate)
+        {
+        }
+
+        /// <summary>
+        /// Inspect the output.
+        /// </summary>
+        /// <param name="output">The output. May be called after linking or binding.</param>
+        /// <remarks>
+        /// To inspect a patch's filtered transforms, enumerate <see cref="Output.SubStorages"/>.
+        /// Transforms where the <see cref="SubStorage.Name"/> begins with "#" are
+        /// called patch transforms and instruct Windows Installer how to apply the
+        /// authored transforms - those that do not begin with "#". The authored
+        /// transforms are the primary transforms you'll typically want to inspect
+        /// and contain your changes to target products.
+        /// </remarks>
+        public virtual void InspectOutput(Output output)
+        {
+        }
+
+        /// <summary>
+        /// Inspect the final output after binding.
+        /// </summary>
+        /// <param name="filePath">The file path to the final bound output.</param>
+        /// <param name="pdb">The <see cref="Pdb"/> that contains source line numbers
+        /// for the database and all rows.</param>
+        public virtual void InspectDatabase(string filePath, Pdb pdb)
+        {
+        }
+    }
+}
diff --git a/src/WixToolset.Extensibility/PreprocessorExtension.cs b/src/WixToolset.Extensibility/PreprocessorExtension.cs
new file mode 100644
index 00000000..2af30a95
--- /dev/null
+++ b/src/WixToolset.Extensibility/PreprocessorExtension.cs
@@ -0,0 +1,99 @@
+// 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.Extensibility
+{
+    using System.Xml.Linq;
+    using WixToolset.Data;
+
+    /// <summary>
+    /// Base class for creating a preprocessor extension.
+    /// </summary>
+    public abstract class PreprocessorExtension : IPreprocessorExtension
+    {
+        /// <summary>
+        /// Gets or sets the preprocessor core for the extension.
+        /// </summary>
+        /// <value>Preprocessor core for the extension.</value>
+        public IPreprocessorCore Core { get; set; }
+
+        /// <summary>
+        /// Gets or sets the variable prefixes for the extension.
+        /// </summary>
+        /// <value>The variable prefixes for the extension.</value>
+        public virtual string[] Prefixes
+        {
+            get { return null; }
+        }
+
+        /// <summary>
+        /// Called at the beginning of the preprocessing of a source file.
+        /// </summary>
+        public virtual void Initialize()
+        {
+        }
+
+        /// <summary>
+        /// Gets the value of a variable whose prefix matches the extension.
+        /// </summary>
+        /// <param name="prefix">The prefix of the variable to be processed by the extension.</param>
+        /// <param name="name">The name of the variable.</param>
+        /// <returns>The value of the variable or null if the variable is undefined.</returns>
+        public virtual string GetVariableValue(string prefix, string name)
+        {
+            return null;
+        }
+
+        /// <summary>
+        /// Evaluates a function defined in the extension.
+        /// </summary>
+        /// <param name="prefix">The prefix of the function to be processed by the extension.</param>
+        /// <param name="function">The name of the function.</param>
+        /// <param name="args">The list of arguments.</param>
+        /// <returns>The value of the function or null if the function is not defined.</returns>
+        public virtual string EvaluateFunction(string prefix, string function, string[] args)
+        {
+            return null;
+        }
+
+        /// <summary>
+        /// Processes a pragma defined in the extension.
+        /// </summary>
+        /// <param name="sourceLineNumbers">The location of this pragma's PI.</param>
+        /// <param name="prefix">The prefix of the pragma to be processed by the extension.</param>
+        /// <param name="pragma">The name of the pragma.</param>
+        /// <param name="args">The pragma's arguments.</param>
+        /// <param name="parent">The parent node of the pragma.</param>
+        /// <returns>false if the pragma is not defined.</returns>
+        /// <comments>Don't return false for any condition except for unrecognized pragmas. Throw errors that are fatal to the compile. use core.OnMessage for warnings and messages.</comments>
+        public virtual bool ProcessPragma(SourceLineNumber sourceLineNumbers, string prefix, string pragma, string args, XContainer parent)
+        {
+            return false;
+        }
+
+        /// <summary>
+        /// Preprocess a document after normal preprocessing has completed.
+        /// </summary>
+        /// <param name="document">The document to preprocess.</param>
+        public virtual void PreprocessDocument(XDocument document)
+        {
+        }
+
+        /// <summary>
+        /// Preprocesses a parameter.
+        /// </summary>
+        /// <param name="name">Name of parameter that matches extension.</param>
+        /// <returns>The value of the parameter after processing.</returns>
+        /// <remarks>By default this method will cause an error if its called.</remarks>
+        public virtual string PreprocessParameter(string name)
+        {
+            return null;
+        }
+
+        /// <summary>
+        /// Called at the end of the preprocessing of a source file.
+        /// </summary>
+        public virtual void Finish()
+        {
+        }
+    }
+}
diff --git a/src/WixToolset.Extensibility/ResolvedCabinet.cs b/src/WixToolset.Extensibility/ResolvedCabinet.cs
new file mode 100644
index 00000000..e98d6d96
--- /dev/null
+++ b/src/WixToolset.Extensibility/ResolvedCabinet.cs
@@ -0,0 +1,20 @@
+// 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.Extensibility
+{
+    /// <summary>
+    /// Data returned from build file manager ResolveCabinet callback.
+    /// </summary>
+    public class ResolvedCabinet
+    {
+        /// <summary>
+        /// Gets or sets the build option for the resolved cabinet.
+        /// </summary>
+        public CabinetBuildOption BuildOption { get; set; }
+
+        /// <summary>
+        /// Gets or sets the path for the resolved cabinet.
+        /// </summary>
+        public string Path { get; set; }
+    }
+}
diff --git a/src/WixToolset.Extensibility/WixToolset.Extensibility.csproj b/src/WixToolset.Extensibility/WixToolset.Extensibility.csproj
new file mode 100644
index 00000000..8efae769
--- /dev/null
+++ b/src/WixToolset.Extensibility/WixToolset.Extensibility.csproj
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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. -->
+
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <Description></Description>
+    <Title>WiX Toolset Extensibility</Title>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <!-- <ProjectOrPackageReference Include="$(WixToolsetRootFolder)Data\src\WixToolset.Data\WixToolset.Data.csproj" Version="4.0.*" /> -->
+    <!--<ProjectOrPackageReference Include="WixToolset.Data" Repo="Data" Version="1.0.*" />-->
+    <ProjectReference Include="$(WixToolsetRootFolder)\Data\src\WixToolset.Data\WixToolset.Data.csproj" Condition=" '$(Configuration)' == 'Debug' And Exists('$(WixToolsetRootFolder)\Data\src\WixToolset.Data\WixToolset.Data.csproj') " />
+    <PackageReference Include="WixToolset.Data" Version="4.0.*" Condition=" '$(Configuration)' == 'Release' Or !Exists('$(WixToolsetRootFolder)\Data\src\WixToolset.Data\WixToolset.Data.csproj') " />
+  </ItemGroup>
+</Project>