diff --git a/.gitignore b/.gitignore
index c424a894c2a6e0..25cf8b2f6f8c3d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -111,10 +111,14 @@ PCbuild/*-pgo
 PCbuild/*.VC.db
 PCbuild/*.VC.opendb
 PCbuild/amd64/
+PCbuild/amd64t/
 PCbuild/arm32/
+PCbuild/arm32t/
 PCbuild/arm64/
+PCbuild/arm64t/
 PCbuild/obj/
 PCbuild/win32/
+PCbuild/win32t/
 Tools/unicode/data/
 /autom4te.cache
 /build/
diff --git a/PC/pyconfig.h.in b/PC/pyconfig.h.in
index d8f0a6be69c21a..8bbf877a5bb5ed 100644
--- a/PC/pyconfig.h.in
+++ b/PC/pyconfig.h.in
@@ -94,6 +94,9 @@ WIN32 is still required for the locale module.
 #endif
 #endif /* Py_BUILD_CORE || Py_BUILD_CORE_BUILTIN || Py_BUILD_CORE_MODULE */
 
+/* Define to 1 if you want to disable the GIL */
+#undef Py_GIL_DISABLED
+
 /* Compiler specific defines */
 
 /* ------------------------------------------------------------------------*/
@@ -305,8 +308,16 @@ Py_NO_ENABLE_SHARED to find out.  Also support MS_NO_COREDLL for b/w compat */
                 /* not building the core - must be an ext */
 #               if defined(_MSC_VER)
                         /* So MSVC users need not specify the .lib
-                        file in their Makefile (other compilers are
-                        generally taken care of by distutils.) */
+                        file in their Makefile */
+#                       if defined(Py_GIL_DISABLED)
+#                       if defined(_DEBUG)
+#                               pragma comment(lib,"python313t_d.lib")
+#                       elif defined(Py_LIMITED_API)
+#                               pragma comment(lib,"python3t.lib")
+#                       else
+#                               pragma comment(lib,"python313t.lib")
+#                       endif /* _DEBUG */
+#                       else /* Py_GIL_DISABLED */
 #                       if defined(_DEBUG)
 #                               pragma comment(lib,"python313_d.lib")
 #                       elif defined(Py_LIMITED_API)
@@ -314,6 +325,7 @@ Py_NO_ENABLE_SHARED to find out.  Also support MS_NO_COREDLL for b/w compat */
 #                       else
 #                               pragma comment(lib,"python313.lib")
 #                       endif /* _DEBUG */
+#                       endif /* Py_GIL_DISABLED */
 #               endif /* _MSC_VER */
 #       endif /* Py_BUILD_CORE */
 #endif /* MS_COREDLL */
@@ -739,7 +751,4 @@ Py_NO_ENABLE_SHARED to find out.  Also support MS_NO_COREDLL for b/w compat */
 /* Define if libssl has X509_VERIFY_PARAM_set1_host and related function */
 #define HAVE_X509_VERIFY_PARAM_SET1_HOST 1
 
-/* Define if you want to disable the GIL */
-#undef Py_GIL_DISABLED
-
 #endif /* !Py_CONFIG_H */
diff --git a/PCbuild/_asyncio.vcxproj b/PCbuild/_asyncio.vcxproj
index ed1e1bc0a420dc..76b0ffd660dba0 100644
--- a/PCbuild/_asyncio.vcxproj
+++ b/PCbuild/_asyncio.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_bz2.vcxproj b/PCbuild/_bz2.vcxproj
index 3fe95fbf83993a..e0dc6ec187a08d 100644
--- a/PCbuild/_bz2.vcxproj
+++ b/PCbuild/_bz2.vcxproj
@@ -80,7 +80,7 @@
   <PropertyGroup Label="Configuration" />
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_ctypes.vcxproj b/PCbuild/_ctypes.vcxproj
index 253da31e9ce182..63d5fa49cd4e17 100644
--- a/PCbuild/_ctypes.vcxproj
+++ b/PCbuild/_ctypes.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_ctypes_test.vcxproj b/PCbuild/_ctypes_test.vcxproj
index 8a01e743a4d86f..97354739c09834 100644
--- a/PCbuild/_ctypes_test.vcxproj
+++ b/PCbuild/_ctypes_test.vcxproj
@@ -80,7 +80,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_decimal.vcxproj b/PCbuild/_decimal.vcxproj
index 0916f1a2d37887..490d7df87eb1c6 100644
--- a/PCbuild/_decimal.vcxproj
+++ b/PCbuild/_decimal.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_elementtree.vcxproj b/PCbuild/_elementtree.vcxproj
index 8da5244bac0cb6..8c9c0e42f7fe3e 100644
--- a/PCbuild/_elementtree.vcxproj
+++ b/PCbuild/_elementtree.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_hashlib.vcxproj b/PCbuild/_hashlib.vcxproj
index 6dad8183c57ae3..2cd205224bc089 100644
--- a/PCbuild/_hashlib.vcxproj
+++ b/PCbuild/_hashlib.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_lzma.vcxproj b/PCbuild/_lzma.vcxproj
index fe076a6fc57168..40107d4b76cd53 100644
--- a/PCbuild/_lzma.vcxproj
+++ b/PCbuild/_lzma.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_multiprocessing.vcxproj b/PCbuild/_multiprocessing.vcxproj
index 77b6bfc8e1e483..a65397f532aa86 100644
--- a/PCbuild/_multiprocessing.vcxproj
+++ b/PCbuild/_multiprocessing.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_overlapped.vcxproj b/PCbuild/_overlapped.vcxproj
index 9e60d3b5db336c..224bf05d5303a0 100644
--- a/PCbuild/_overlapped.vcxproj
+++ b/PCbuild/_overlapped.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_queue.vcxproj b/PCbuild/_queue.vcxproj
index 8065b235851686..80a1c3c6a4ad3e 100644
--- a/PCbuild/_queue.vcxproj
+++ b/PCbuild/_queue.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_socket.vcxproj b/PCbuild/_socket.vcxproj
index 78fa4d6729abb9..41af0895921bbb 100644
--- a/PCbuild/_socket.vcxproj
+++ b/PCbuild/_socket.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_sqlite3.vcxproj b/PCbuild/_sqlite3.vcxproj
index 57c7413671e54e..9ae0a0fc3a009d 100644
--- a/PCbuild/_sqlite3.vcxproj
+++ b/PCbuild/_sqlite3.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_ssl.vcxproj b/PCbuild/_ssl.vcxproj
index 226ff506f8c62b..d4e1affab031d7 100644
--- a/PCbuild/_ssl.vcxproj
+++ b/PCbuild/_ssl.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_testbuffer.vcxproj b/PCbuild/_testbuffer.vcxproj
index 917d7ae50feb14..4e721e8ce09f0c 100644
--- a/PCbuild/_testbuffer.vcxproj
+++ b/PCbuild/_testbuffer.vcxproj
@@ -80,7 +80,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_testcapi.vcxproj b/PCbuild/_testcapi.vcxproj
index 1c15541d3ec735..6911aacab29b97 100644
--- a/PCbuild/_testcapi.vcxproj
+++ b/PCbuild/_testcapi.vcxproj
@@ -80,7 +80,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_testclinic.vcxproj b/PCbuild/_testclinic.vcxproj
index e319b3c0f42e0f..ef981332c6ab03 100644
--- a/PCbuild/_testclinic.vcxproj
+++ b/PCbuild/_testclinic.vcxproj
@@ -80,7 +80,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
@@ -107,4 +107,4 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/PCbuild/_testclinic_limited.vcxproj b/PCbuild/_testclinic_limited.vcxproj
index b00b2be491b423..183a55080e8693 100644
--- a/PCbuild/_testclinic_limited.vcxproj
+++ b/PCbuild/_testclinic_limited.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_testconsole.vcxproj b/PCbuild/_testconsole.vcxproj
index 5d7e14eff10294..69d312b17a5a62 100644
--- a/PCbuild/_testconsole.vcxproj
+++ b/PCbuild/_testconsole.vcxproj
@@ -80,7 +80,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_testimportmultiple.vcxproj b/PCbuild/_testimportmultiple.vcxproj
index 6d80d5779f24d8..c35ac83c1c739f 100644
--- a/PCbuild/_testimportmultiple.vcxproj
+++ b/PCbuild/_testimportmultiple.vcxproj
@@ -80,7 +80,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_testinternalcapi.vcxproj b/PCbuild/_testinternalcapi.vcxproj
index 558f66ca95cd33..a825cac9138674 100644
--- a/PCbuild/_testinternalcapi.vcxproj
+++ b/PCbuild/_testinternalcapi.vcxproj
@@ -80,7 +80,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_testmultiphase.vcxproj b/PCbuild/_testmultiphase.vcxproj
index 430eb528cc3927..e730fe308ab835 100644
--- a/PCbuild/_testmultiphase.vcxproj
+++ b/PCbuild/_testmultiphase.vcxproj
@@ -80,7 +80,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_testsinglephase.vcxproj b/PCbuild/_testsinglephase.vcxproj
index fb4bcd953923f8..bf4dabf66c1040 100644
--- a/PCbuild/_testsinglephase.vcxproj
+++ b/PCbuild/_testsinglephase.vcxproj
@@ -80,7 +80,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_tkinter.vcxproj b/PCbuild/_tkinter.vcxproj
index 30cedcbb43de76..117488a01621cc 100644
--- a/PCbuild/_tkinter.vcxproj
+++ b/PCbuild/_tkinter.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_uuid.vcxproj b/PCbuild/_uuid.vcxproj
index 2437b7eb2d9399..50d81cc7916dbd 100644
--- a/PCbuild/_uuid.vcxproj
+++ b/PCbuild/_uuid.vcxproj
@@ -80,7 +80,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_wmi.vcxproj b/PCbuild/_wmi.vcxproj
index c1914a3fa5a1bf..22fa8960982528 100644
--- a/PCbuild/_wmi.vcxproj
+++ b/PCbuild/_wmi.vcxproj
@@ -80,7 +80,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/_zoneinfo.vcxproj b/PCbuild/_zoneinfo.vcxproj
index 6e6389c3773397..47b5bfa5b8815a 100644
--- a/PCbuild/_zoneinfo.vcxproj
+++ b/PCbuild/_zoneinfo.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/pyexpat.vcxproj b/PCbuild/pyexpat.vcxproj
index 001f8afd89b9e9..dc9161a8b290f9 100644
--- a/PCbuild/pyexpat.vcxproj
+++ b/PCbuild/pyexpat.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/pyproject.props b/PCbuild/pyproject.props
index 68c0550f7603b7..de374a71f559d2 100644
--- a/PCbuild/pyproject.props
+++ b/PCbuild/pyproject.props
@@ -23,6 +23,13 @@
     <LinkIncremental Condition="$(Configuration) != 'Debug'">false</LinkIncremental>
   </PropertyGroup>
 
+  <PropertyGroup>
+    <TargetNameExt>$(TargetName)$(TargetExt)</TargetNameExt>
+    <_TargetNameSep>$(TargetNameExt.LastIndexOf(`.`))</_TargetNameSep>
+    <TargetName>$(TargetNameExt.Substring(0, $(_TargetNameSep)))</TargetName>
+    <TargetExt>$(TargetNameExt.Substring($(_TargetNameSep)))</TargetExt>
+  </PropertyGroup>
+
   <PropertyGroup Label="MSVC Bug Workarounds" Condition="$(VCToolsVersion) != ''">
     <_VCToolsVersion>$([System.Version]::Parse(`$(VCToolsVersion)`).Major).$([System.Version]::Parse(`$(VCToolsVersion)`).Minor)</_VCToolsVersion>
 
@@ -36,7 +43,7 @@
     <_PlatformPreprocessorDefinition>_WIN32;</_PlatformPreprocessorDefinition>
     <_PlatformPreprocessorDefinition Condition="$(Platform) == 'x64'">_WIN64;</_PlatformPreprocessorDefinition>
     <_PlatformPreprocessorDefinition Condition="$(Platform) == 'x64' and $(PlatformToolset) != 'ClangCL'">_M_X64;$(_PlatformPreprocessorDefinition)</_PlatformPreprocessorDefinition>
-    <_Py3NamePreprocessorDefinition>PY3_DLLNAME=L"$(Py3DllName)";</_Py3NamePreprocessorDefinition>
+    <_Py3NamePreprocessorDefinition>PY3_DLLNAME=L"$(Py3DllName)$(PyDebugExt)";</_Py3NamePreprocessorDefinition>
   </PropertyGroup>
   <ItemDefinitionGroup>
     <ClCompile>
@@ -155,8 +162,8 @@ public override bool Execute() {
   </UsingTask>
 
   <Target Name="KillPython" BeforeTargets="PrepareForBuild" Condition="'$(KillPython)' == 'true'">
-    <Message Text="Killing any running python$(PyDebugExt)$(PyTestExt).exe instances..." Importance="high" />
-    <KillPython FileName="$(OutDir)python$(PyDebugExt)$(PyTestExt).exe" />
+    <Message Text="Killing any running $(PyExeName)$(PyDebugExt)$(PyTestExt).exe instances..." Importance="high" />
+    <KillPython FileName="$(OutDir)$(PyExeName)$(PyDebugExt)$(PyTestExt).exe" />
   </Target>
 
   <!--
diff --git a/PCbuild/python.props b/PCbuild/python.props
index 496bc3dd4cf794..ae49c86cdf00a6 100644
--- a/PCbuild/python.props
+++ b/PCbuild/python.props
@@ -31,11 +31,13 @@
     <ArchName Condition="'$(ArchName)' == '' and $(Platform) == 'ARM'">arm32</ArchName>
     <ArchName Condition="'$(ArchName)' == '' and $(Platform) == 'ARM64'">arm64</ArchName>
     <ArchName Condition="'$(ArchName)' == ''">win32</ArchName>
-    
+
     <!-- Root directory of the repository -->
     <PySourcePath Condition="'$(PySourcePath)' == ''">$([System.IO.Path]::GetFullPath($(MSBuildThisFileDirectory)\..\))</PySourcePath>
     <PySourcePath Condition="!HasTrailingSlash($(PySourcePath))">$(PySourcePath)\</PySourcePath>
-    
+  </PropertyGroup>
+
+  <PropertyGroup Condition="$(DisableGil) != 'true'">
     <!-- Directory where build outputs are put -->
     <BuildPath32 Condition="'$(Py_OutDir)' == ''">$(PySourcePath)PCbuild\win32\</BuildPath32>
     <BuildPath32 Condition="'$(Py_OutDir)' != ''">$(Py_OutDir)\win32\</BuildPath32>
@@ -52,7 +54,30 @@
     <BuildPath Condition="'$(BuildPath)' == ''">$(PySourcePath)PCbuild\$(ArchName)\</BuildPath>
     <BuildPath Condition="!HasTrailingSlash($(BuildPath))">$(BuildPath)\</BuildPath>
     <BuildPath Condition="$(Configuration) == 'PGInstrument'">$(BuildPath)instrumented\</BuildPath>
-    
+
+    <!-- VPATH definition (escaped) -->
+    <PyVPath Condition="$(Configuration) != 'PGInstrument'">..\\..</PyVPath>
+    <PyVPath Condition="$(Configuration) == 'PGInstrument'">..\\..\\..</PyVPath>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="$(DisableGil) == 'true'">
+    <!-- Directory where build outputs are put -->
+    <BuildPath32 Condition="'$(Py_OutDir)' == ''">$(PySourcePath)PCbuild\win32t\</BuildPath32>
+    <BuildPath32 Condition="'$(Py_OutDir)' != ''">$(Py_OutDir)\win32t\</BuildPath32>
+    <BuildPath64 Condition="'$(Py_OutDir)' == ''">$(PySourcePath)PCbuild\amd64t\</BuildPath64>
+    <BuildPath64 Condition="'$(Py_OutDir)' != ''">$(Py_OutDir)\amd64t\</BuildPath64>
+    <BuildPathArm32 Condition="'$(Py_OutDir)' == ''">$(PySourcePath)PCbuild\arm32t\</BuildPathArm32>
+    <BuildPathArm32 Condition="'$(Py_OutDir)' != ''">$(Py_OutDir)\arm32t\</BuildPathArm32>
+    <BuildPathArm64 Condition="'$(Py_OutDir)' == ''">$(PySourcePath)PCbuild\arm64t\</BuildPathArm64>
+    <BuildPathArm64 Condition="'$(Py_OutDir)' != ''">$(Py_OutDir)\arm64t\</BuildPathArm64>
+    <BuildPath Condition="'$(ArchName)' == 'win32'">$(BuildPath32)</BuildPath>
+    <BuildPath Condition="'$(ArchName)' == 'amd64'">$(BuildPath64)</BuildPath>
+    <BuildPath Condition="'$(ArchName)' == 'arm32'">$(BuildPathArm32)</BuildPath>
+    <BuildPath Condition="'$(ArchName)' == 'arm64'">$(BuildPathArm64)</BuildPath>
+    <BuildPath Condition="'$(BuildPath)' == ''">$(PySourcePath)PCbuild\$(ArchName)t\</BuildPath>
+    <BuildPath Condition="!HasTrailingSlash($(BuildPath))">$(BuildPath)\</BuildPath>
+    <BuildPath Condition="$(Configuration) == 'PGInstrument'">$(BuildPath)instrumented\</BuildPath>
+
     <!-- VPATH definition (escaped) -->
     <PyVPath Condition="$(Configuration) != 'PGInstrument'">..\\..</PyVPath>
     <PyVPath Condition="$(Configuration) == 'PGInstrument'">..\\..\\..</PyVPath>
@@ -84,22 +109,19 @@
   <PropertyGroup>
     <!-- Suffix for all binaries when building for debug -->
     <PyDebugExt Condition="'$(PyDebugExt)' == '' and $(Configuration) == 'Debug'">_d</PyDebugExt>
-    
+
     <!-- Suffix for versions/keys when building with test markers -->
     <PyTestExt Condition="$(UseTestMarker) == 'true'">-test</PyTestExt>
-    
+
     <!-- Suffix for versions/keys when building for particular platforms -->
     <PyArchExt Condition="'$(ArchName)' == 'win32'">-32</PyArchExt>
     <PyArchExt Condition="'$(ArchName)' == 'arm32'">-arm32</PyArchExt>
     <PyArchExt Condition="'$(ArchName)' == 'arm64'">-arm64</PyArchExt>
-    
-    <!-- Full path of the resulting python.exe binary -->
-    <PythonExe Condition="'$(PythonExe)' == ''">$(BuildPath)python$(PyDebugExt).exe</PythonExe>
 
     <!-- Include Tkinter by default -->
     <IncludeTkinter Condition="'$(IncludeTkinter)' == ''">true</IncludeTkinter>
   </PropertyGroup>
-  
+
   <PropertyGroup Condition="'$(Platform)'=='ARM'" Label="ArmConfiguration">
     <WindowsSDKDesktopARMSupport>true</WindowsSDKDesktopARMSupport>
   </PropertyGroup>
@@ -141,7 +163,7 @@
   <PropertyGroup Condition="'$(OverrideVersion)' == ''">
     <!--
     Read version information from Include\patchlevel.h. The following properties are set:
-    
+
         MajorVersionNumber  -   the '3' in '3.5.2a1'
         MinorVersionNumber  -   the '5' in '3.5.2a1'
         MicroVersionNumber  -   the '2' in '3.5.2a1'
@@ -167,22 +189,22 @@
     <ReleaseLevelName Condition="$(_ReleaseLevel) == 'BETA'">b$(ReleaseSerial)</ReleaseLevelName>
     <ReleaseLevelName Condition="$(_ReleaseLevel) == 'GAMMA'">rc$(ReleaseSerial)</ReleaseLevelName>
   </PropertyGroup>
-  
+
   <PropertyGroup Condition="'$(OverrideVersion)' != ''">
     <!--
     Override the version number when building by specifying OverrideVersion.
     For example:
-    
+
         PCbuild\build.bat "/p:OverrideVersion=3.5.2a1"
-    
+
     Use the -V option to check your version is valid:
-    
+
         PCbuild\build.bat -V "/p:OverrideVersion=3.5.2a1"
           PythonVersionNumber: 3.5.2
           PythonVersion:       3.5.2a1
           PythonVersionHex:    0x030502A1
           Field3Value:         2101
-    
+
     Note that this only affects the version numbers embedded in resources and
     installers, but not sys.version.
     -->
@@ -223,22 +245,50 @@
         ))
     ))</Field3Value>
     <Field3Value Condition="$(UseTestMarker) == 'true'">$([msbuild]::Add($(Field3Value), 9000))</Field3Value>
-    
+
+    <!-- Name and full path of the resulting python.exe binary -->
+    <PyExeName Condition="$(DisableGil) == 'true'">python$(MajorVersionNumber).$(MinorVersionNumber)t</PyExeName>
+    <PyExeName Condition="$(PyExeName) == ''">python</PyExeName>
+    <PythonExe Condition="'$(PythonExe)' == ''">$(BuildPath)$(PyExeName)$(PyDebugExt).exe</PythonExe>
+    <PyWExeName Condition="$(DisableGil) == 'true'">pythonw$(MajorVersionNumber).$(MinorVersionNumber)t</PyWExeName>
+    <PyWExeName Condition="$(PyWExeName) == ''">pythonw</PyWExeName>
+
     <!-- The name of the resulting pythonXY.dll (without the extension) -->
-    <PyDllName>python$(MajorVersionNumber)$(MinorVersionNumber)$(PyDebugExt)</PyDllName>
+    <PyDllName Condition="$(DisableGil) == 'true'">python$(MajorVersionNumber)$(MinorVersionNumber)t$(PyDebugExt)</PyDllName>
+    <PyDllName Condition="$(PyDllName) == ''">python$(MajorVersionNumber)$(MinorVersionNumber)$(PyDebugExt)</PyDllName>
     <!-- The name of the resulting pythonX.dll (without the extension) -->
-    <Py3DllName>python3$(PyDebugExt)</Py3DllName>
+    <Py3DllName Condition="$(DisableGil) == 'true'">python3t</Py3DllName>
+    <Py3DllName Condition="$(Py3DllName) == ''">python3</Py3DllName>
+  </PropertyGroup>
 
+  <PropertyGroup Condition="$(DisableGil) != 'true'">
     <!-- The version and platform tag to include in .pyd filenames -->
     <PydTag Condition="$(ArchName) == 'win32'">.cp$(MajorVersionNumber)$(MinorVersionNumber)-win32</PydTag>
     <PydTag Condition="$(ArchName) == 'arm32'">.cp$(MajorVersionNumber)$(MinorVersionNumber)-win_arm32</PydTag>
     <PydTag Condition="$(ArchName) == 'arm64'">.cp$(MajorVersionNumber)$(MinorVersionNumber)-win_arm64</PydTag>
     <PydTag Condition="$(ArchName) == 'amd64'">.cp$(MajorVersionNumber)$(MinorVersionNumber)-win_amd64</PydTag>
-    
+
+    <!-- The extension to use for standard library PYDs -->
+    <PyStdlibPydExt>.pyd</PyStdlibPydExt>
+
     <!-- The version number for sys.winver -->
     <SysWinVer>$(MajorVersionNumber).$(MinorVersionNumber)$(PyArchExt)$(PyTestExt)</SysWinVer>
   </PropertyGroup>
-  
+
+  <PropertyGroup Condition="$(DisableGil) == 'true'">
+    <!-- The version and platform tag to include in .pyd filenames -->
+    <PydTag Condition="$(ArchName) == 'win32'">.cp$(MajorVersionNumber)$(MinorVersionNumber)t-win32</PydTag>
+    <PydTag Condition="$(ArchName) == 'arm32'">.cp$(MajorVersionNumber)$(MinorVersionNumber)t-win_arm32</PydTag>
+    <PydTag Condition="$(ArchName) == 'arm64'">.cp$(MajorVersionNumber)$(MinorVersionNumber)t-win_arm64</PydTag>
+    <PydTag Condition="$(ArchName) == 'amd64'">.cp$(MajorVersionNumber)$(MinorVersionNumber)t-win_amd64</PydTag>
+
+    <!-- The extension to use for standard library PYDs -->
+    <PyStdlibPydExt>$(PydTag).pyd</PyStdlibPydExt>
+
+    <!-- The version number for sys.winver -->
+    <SysWinVer>$(MajorVersionNumber).$(MinorVersionNumber)t$(PyArchExt)$(PyTestExt)</SysWinVer>
+  </PropertyGroup>
+
   <!-- Displays the calculated version info -->
   <Target Name="ShowVersionInfo">
     <Message Importance="high" Text="PythonVersionNumber: $(PythonVersionNumber)" />
diff --git a/PCbuild/python.vcxproj b/PCbuild/python.vcxproj
index 8b733865962373..4b011808b604a2 100644
--- a/PCbuild/python.vcxproj
+++ b/PCbuild/python.vcxproj
@@ -72,6 +72,7 @@
   <Import Project="python.props" />
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Label="Configuration">
+    <TargetName>$(PyExeName)</TargetName>
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
     <CharacterSet>MultiByte</CharacterSet>
@@ -129,7 +130,7 @@
     </PropertyGroup>
     <Exec Command='setlocal
 set PYTHONPATH=$(PySourcePath)Lib
-"$(OutDir)python$(PyDebugExt).exe" "$(PySourcePath)PC\validate_ucrtbase.py" $(UcrtName)' ContinueOnError="true" />
+"$(OutDir)$(PyExeName)$(PyDebugExt).exe" "$(PySourcePath)PC\validate_ucrtbase.py" $(UcrtName)' ContinueOnError="true" />
   </Target>
   <Target Name="GeneratePythonBat" AfterTargets="AfterBuild">
     <PropertyGroup>
@@ -142,7 +143,7 @@ set PYTHONPATH=$(PySourcePath)Lib
 @echo Running $(Configuration)^|$(Platform) interpreter...
 @setlocal
 @set PYTHONHOME=$(PySourcePath)
-@"$(OutDir)python$(PyDebugExt).exe" %*
+@"$(OutDir)$(PyExeName)$(PyDebugExt).exe" %*
 </_Content>
       <_ExistingContent Condition="Exists('$(PySourcePath)python.bat')">$([System.IO.File]::ReadAllText('$(PySourcePath)python.bat'))</_ExistingContent>
     </PropertyGroup>
diff --git a/PCbuild/python3dll.vcxproj b/PCbuild/python3dll.vcxproj
index ec22e6fc76e584..235ea1cf9d33fb 100644
--- a/PCbuild/python3dll.vcxproj
+++ b/PCbuild/python3dll.vcxproj
@@ -70,12 +70,12 @@
     <ProjectGuid>{885D4898-D08D-4091-9C40-C700CFE3FC5A}</ProjectGuid>
     <RootNamespace>python3dll</RootNamespace>
     <Keyword>Win32Proj</Keyword>
-    <TargetName>python3</TargetName>
     <SupportPGO>false</SupportPGO>
   </PropertyGroup>
   <Import Project="python.props" />
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Label="Configuration">
+    <TargetName>$(Py3DllName)</TargetName>
     <ConfigurationType>DynamicLibrary</ConfigurationType>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
diff --git a/PCbuild/pythonw.vcxproj b/PCbuild/pythonw.vcxproj
index e23635e5ea9411..d4db3caf774061 100644
--- a/PCbuild/pythonw.vcxproj
+++ b/PCbuild/pythonw.vcxproj
@@ -73,6 +73,7 @@
   <Import Project="python.props" />
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Label="Configuration">
+    <TargetName>$(PyWExeName)</TargetName>
     <ConfigurationType>Application</ConfigurationType>
     <UseOfMfc>false</UseOfMfc>
   </PropertyGroup>
diff --git a/PCbuild/select.vcxproj b/PCbuild/select.vcxproj
index 750a713949919a..d7448fd4d72380 100644
--- a/PCbuild/select.vcxproj
+++ b/PCbuild/select.vcxproj
@@ -78,7 +78,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/sqlite3.vcxproj b/PCbuild/sqlite3.vcxproj
index c502d51833b91a..6bcc4e913c8e77 100644
--- a/PCbuild/sqlite3.vcxproj
+++ b/PCbuild/sqlite3.vcxproj
@@ -69,12 +69,12 @@
   <PropertyGroup Label="Globals">
     <ProjectGuid>{A1A295E5-463C-437F-81CA-1F32367685DA}</ProjectGuid>
     <RootNamespace>sqlite3</RootNamespace>
-    <TargetExt>.pyd</TargetExt>
     <SupportPGO>false</SupportPGO>
   </PropertyGroup>
   <Import Project="python.props" />
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Label="Configuration">
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
     <ConfigurationType>DynamicLibrary</ConfigurationType>
     <CharacterSet>NotSet</CharacterSet>
   </PropertyGroup>
diff --git a/PCbuild/unicodedata.vcxproj b/PCbuild/unicodedata.vcxproj
index addef753359ed6..781f938e2ab78e 100644
--- a/PCbuild/unicodedata.vcxproj
+++ b/PCbuild/unicodedata.vcxproj
@@ -79,7 +79,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/winsound.vcxproj b/PCbuild/winsound.vcxproj
index 32cedc9b444902..c26029b15a339f 100644
--- a/PCbuild/winsound.vcxproj
+++ b/PCbuild/winsound.vcxproj
@@ -80,7 +80,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/xxlimited.vcxproj b/PCbuild/xxlimited.vcxproj
index 1c776fb0da3e72..093e6920c0b76c 100644
--- a/PCbuild/xxlimited.vcxproj
+++ b/PCbuild/xxlimited.vcxproj
@@ -80,7 +80,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>
diff --git a/PCbuild/xxlimited_35.vcxproj b/PCbuild/xxlimited_35.vcxproj
index dd830b3b6aaa91..3f4d4463f24af0 100644
--- a/PCbuild/xxlimited_35.vcxproj
+++ b/PCbuild/xxlimited_35.vcxproj
@@ -80,7 +80,7 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <PropertyGroup>
-    <TargetExt>.pyd</TargetExt>
+    <TargetExt>$(PyStdlibPydExt)</TargetExt>
   </PropertyGroup>
   <ImportGroup Label="ExtensionSettings">
   </ImportGroup>