diff --git a/windows-release/azure-pipelines.yml b/windows-release/azure-pipelines.yml
index f06dbc01..ee5f8adf 100644
--- a/windows-release/azure-pipelines.yml
+++ b/windows-release/azure-pipelines.yml
@@ -39,6 +39,10 @@ parameters:
   displayName: "Signature description"
   type: string
   default: 'Built: $(Build.BuildNumber)'
+- name: DoFreethreaded
+  displayName: "Include free-threaded builds (3.13 and later)"
+  type: boolean
+  default: true
 - name: DoARM64
   displayName: "Publish ARM64 build (3.11 and later)"
   type: boolean
@@ -106,6 +110,7 @@ variables:
   ${{ else }}:
     IsRealSigned: false
   DoCHM: ${{ parameters.DoCHM }}
+  DoFreethreaded: ${{ parameters.DoFreethreaded }}
   DoLayout: ${{ parameters.DoLayout }}
   DoMSIX: ${{ parameters.DoMSIX }}
   DoNuget: ${{ parameters.DoNuget }}
@@ -128,6 +133,7 @@ stages:
     - template: stage-build.yml
       parameters:
         ARM64TclTk: ${{ parameters.ARM64TclTk }}
+        DoFreethreaded: ${{ parameters.DoFreethreaded }}
         DoPGO: ${{ parameters.DoPGO }}
         DoPGOARM64: ${{ parameters.DoPGOARM64 }}
 
@@ -147,8 +153,11 @@ stages:
     - template: stage-layout-full.yml
       parameters:
         ARM64TclTk: ${{ parameters.ARM64TclTk }}
+        DoFreethreaded: ${{ parameters.DoFreethreaded }}
     - template: stage-layout-embed.yml
     - template: stage-layout-nuget.yml
+      parameters:
+        DoFreethreaded: ${{ parameters.DoFreethreaded }}
 
   - stage: Pack
     dependsOn: Layout
@@ -157,12 +166,15 @@ stages:
       parameters:
         ${{ if and(parameters.SigningCertificate, ne(parameters.SigningCertificate, 'Unsigned')) }}:
           SigningCertificate: ${{ parameters.SigningCertificate }}
+        DoFreethreaded: ${{ parameters.DoFreethreaded }}
 
   - stage: Test
     dependsOn: Pack
     jobs:
     - template: stage-test-embed.yml
     - template: stage-test-nuget.yml
+      parameters:
+        DoFreethreaded: ${{ parameters.DoFreethreaded }}
 
   - ${{ if eq(parameters.DoMSIX, 'true') }}:
     - stage: Layout_MSIX
@@ -192,12 +204,15 @@ stages:
           ARM64TclTk: ${{ parameters.ARM64TclTk }}
           ${{ if and(parameters.SigningCertificate, ne(parameters.SigningCertificate, 'Unsigned')) }}:
             SigningCertificate: ${{ parameters.SigningCertificate }}
+          DoFreethreaded: ${{ parameters.DoFreethreaded }}
 
     - stage: Test_MSI
       displayName: Test MSI installer
       dependsOn: Build_MSI
       jobs:
       - template: stage-test-msi.yml
+        parameters:
+          DoFreethreaded: ${{ parameters.DoFreethreaded }}
 
   - ${{ if eq(parameters.DoPublish, 'true') }}:
     - ${{ if eq(parameters.DoMSI, 'true') }}:
diff --git a/windows-release/build-steps-pgo.yml b/windows-release/build-steps-pgo.yml
index 32c8a670..fa18a047 100644
--- a/windows-release/build-steps-pgo.yml
+++ b/windows-release/build-steps-pgo.yml
@@ -2,6 +2,7 @@ parameters:
   PGInstrument: false
   PGRun: false
   PGUpdate: false
+  DoFreethreaded: false
 
 steps:
 - template: ./checkout.yml
@@ -28,6 +29,15 @@ steps:
       IncludeUwp: true
       Py_OutDir: '$(Build.BinariesDirectory)\bin'
 
+  - ${{ if eq(parameters.DoFreethreaded, 'true') }}:
+    - powershell: |
+        $env:SigningCertificate = $null
+        .\PCbuild\build.bat -v -p $(Platform) -c PGInstrument --disable-gil
+      displayName: 'Run free-threaded build'
+      env:
+        IncludeUwp: true
+        Py_OutDir: '$(Build.BinariesDirectory)\bin'
+
   - ${{ if ne(parameters.PGRun, 'true') }}:
     # Not running in this job, so we publish our entire build and object files
 
@@ -66,6 +76,16 @@ steps:
     env:
       PYTHONHOME: '$(Build.SourcesDirectory)'
 
+  - ${{ if eq(parameters.DoFreethreaded, 'true') }}:
+    - powershell: |
+        $exe = (gci "$(Build.BinariesDirectory)\bin\$(Arch)\instrumented\python3*t.exe" | select -First 1)
+        & $exe -m test --pgo
+      ignoreLASTEXITCODE: true
+      displayName: 'Collect free-threaded profile'
+      env:
+        PYTHONHOME: '$(Build.SourcesDirectory)'
+
+
   - ${{ if ne(parameters.PGUpdate, 'true') }}:
     # Not finishing in this job, so publish the binaries
     - task: PublishPipelineArtifact@0
@@ -107,6 +127,15 @@ steps:
       IncludeUwp: true
       Py_OutDir: '$(Build.BinariesDirectory)\bin'
 
+  - ${{ if eq(parameters.DoFreethreaded, 'true') }}:
+    - powershell: |
+        $env:SigningCertificate = $null
+        .\PCbuild\build.bat -v -p $(Platform) -c PGUpdate --disable-gil
+      displayName: 'Run free-threaded build with PGO'
+      env:
+        IncludeUwp: true
+        Py_OutDir: '$(Build.BinariesDirectory)\bin'
+
   - powershell: |
       $kitroot = (gp 'HKLM:\SOFTWARE\Microsoft\Windows Kits\Installed Roots\').KitsRoot10
       $tool = (gci -r "$kitroot\Bin\*\x64\signtool.exe" | sort FullName -Desc | select -First 1)
diff --git a/windows-release/build-steps.yml b/windows-release/build-steps.yml
index 228b93a4..0bee73b8 100644
--- a/windows-release/build-steps.yml
+++ b/windows-release/build-steps.yml
@@ -1,5 +1,6 @@
 parameters:
   ShouldPGO: false
+  DoFreethreaded: false
 
 steps:
 - template: ./checkout.yml
@@ -15,6 +16,12 @@ steps:
     Write-Host "##vso[build.addbuildtag]$($d.PythonVersion)-$(Name)"
   displayName: 'Extract version numbers'
 
+- ${{ if eq(parameters.DoFreethreaded, 'true') }}:
+  - powershell: |
+      Write-Host "##vso[build.addbuildtag]freethreaded"
+      Write-Host "##vso[build.addbuildtag]$(VersionText)-freethreaded"
+    displayName: 'Add freethreaded tags'
+
 - ${{ if eq(parameters.ShouldPGO, 'false') }}:
   - powershell: |
       $env:SigningCertificate = $null
@@ -24,6 +31,15 @@ steps:
       IncludeUwp: true
       Py_OutDir: '$(Build.BinariesDirectory)\bin'
 
+  - ${{ if eq(parameters.DoFreethreaded, 'true') }}:
+    - powershell: |
+        $env:SigningCertificate = $null
+        .\PCbuild\build.bat -v -p $(Platform) -c $(Configuration) --disable-gil
+      displayName: 'Run free-threaded build'
+      env:
+        IncludeUwp: true
+        Py_OutDir: '$(Build.BinariesDirectory)\bin'
+
 - ${{ if eq(parameters.ShouldPGO, 'true') }}:
   - powershell: |
       $env:SigningCertificate = $null
@@ -33,6 +49,15 @@ steps:
       IncludeUwp: true
       Py_OutDir: '$(Build.BinariesDirectory)\bin'
 
+  - ${{ if eq(parameters.DoFreethreaded, 'true') }}:
+    - powershell: |
+        $env:SigningCertificate = $null
+        .\PCbuild\build.bat -v -p $(Platform) --pgo --disable-gil
+      displayName: 'Run free-threaded build'
+      env:
+        IncludeUwp: true
+        Py_OutDir: '$(Build.BinariesDirectory)\bin'
+
 - powershell: |
     $kitroot = (gp 'HKLM:\SOFTWARE\Microsoft\Windows Kits\Installed Roots\').KitsRoot10
     $tool = (gci -r "$kitroot\Bin\*\x64\signtool.exe" | sort FullName -Desc | select -First 1)
diff --git a/windows-release/msi-steps.yml b/windows-release/msi-steps.yml
index 89f3150a..d9e14ccd 100644
--- a/windows-release/msi-steps.yml
+++ b/windows-release/msi-steps.yml
@@ -1,5 +1,6 @@
 parameters:
   ARM64TclTk: true
+  DoFreethreaded: false
   SigningCertificate: ''
 
 steps:
@@ -90,7 +91,7 @@ steps:
       call Tools\msi\get_externals.bat
       call PCbuild\find_python.bat
       echo ##vso[task.setvariable variable=PYTHON]%PYTHON%
-      call PCbuild/find_msbuild.bat
+      call PCbuild\find_msbuild.bat
       echo ##vso[task.setvariable variable=MSBUILD]%MSBUILD%
     displayName: 'Get external dependencies'
 
@@ -106,6 +107,12 @@ steps:
       gc msbuild.rsp
     displayName: 'Generate response file'
 
+  - ${{ if eq(parameters.DoFreethreaded, 'true') }}:
+    - powershell: |
+        "/p:IncludeFreethreaded=true" | Out-File "$(ResponseFile)" -Append -Encoding UTF8
+        gc "$(ResponseFile)"
+      displayName: 'Add Include_freethreaded to response file'
+
   - ${{ if parameters.SigningCertificate }}:
     - task: DotNetCoreCLI@2
       inputs:
diff --git a/windows-release/purge.py b/windows-release/purge.py
index de9fdc95..c5f2c10c 100644
--- a/windows-release/purge.py
+++ b/windows-release/purge.py
@@ -37,6 +37,9 @@
     "exe.msi",
     "exe_d.msi",
     "exe_pdb.msi",
+    "freethreaded.msi",
+    "freethreaded_d.msi",
+    "freethreaded_pdb.msi",
     "launcher.msi",
     "lib.msi",
     "lib_d.msi",
diff --git a/windows-release/stage-build.yml b/windows-release/stage-build.yml
index ce9e30d9..7a98b376 100644
--- a/windows-release/stage-build.yml
+++ b/windows-release/stage-build.yml
@@ -3,6 +3,7 @@ parameters:
   DoPGO: false
   # DoPGOARM64 only applies if DoPGO is also true
   DoPGOARM64: true
+  DoFreethreaded: false
 
 jobs:
 - job: Build_Docs
@@ -95,6 +96,8 @@ jobs:
 
   steps:
     - template: ./build-steps.yml
+      parameters:
+        DoFreethreaded: ${{ parameters.DoFreethreaded }}
 
 
 - ${{ if eq(parameters.DoPGO, 'true') }}:
@@ -118,6 +121,7 @@ jobs:
     steps:
       - template: ./build-steps-pgo.yml
         parameters:
+          DoFreethreaded: ${{ parameters.DoFreethreaded }}
           PGInstrument: true
           PGRun: true
           PGUpdate: true
@@ -143,6 +147,7 @@ jobs:
       steps:
         - template: ./build-steps-pgo.yml
           parameters:
+            DoFreethreaded: ${{ parameters.DoFreethreaded }}
             PGInstrument: true
 
     - job: Build_Python_PGO_2
@@ -168,6 +173,7 @@ jobs:
       steps:
         - template: ./build-steps-pgo.yml
           parameters:
+            DoFreethreaded: ${{ parameters.DoFreethreaded }}
             PGRun: true
 
     - job: Build_Python_PGO_3
@@ -191,6 +197,7 @@ jobs:
       steps:
         - template: ./build-steps-pgo.yml
           parameters:
+            DoFreethreaded: ${{ parameters.DoFreethreaded }}
             PGUpdate: true
 
 
diff --git a/windows-release/stage-layout-full.yml b/windows-release/stage-layout-full.yml
index 343ee1f7..3eb45ca3 100644
--- a/windows-release/stage-layout-full.yml
+++ b/windows-release/stage-layout-full.yml
@@ -1,5 +1,6 @@
 parameters:
   ARM64TclTk: true
+  DoFreethreaded: false
 
 jobs:
 - job: Make_Layouts
@@ -73,8 +74,22 @@ jobs:
     env:
       TCL_LIBRARY: $(TclLibrary)
 
+  - ${{ if eq(parameters.DoFreethreaded, 'true') }}:
+    - powershell: |
+        $(LayoutCmd) --copy "$(Build.ArtifactStagingDirectory)\layout_freethreaded" --preset-default --include-freethreaded
+      displayName: 'Generate full freethreaded layout'
+      env:
+        TCL_LIBRARY: $(TclLibrary)
+
   - task: PublishPipelineArtifact@0
     displayName: 'Publish Artifact: layout_full_$(Name)'
     inputs:
       targetPath: '$(Build.ArtifactStagingDirectory)\layout'
       artifactName: layout_full_$(Name)
+
+  - ${{ if eq(parameters.DoFreethreaded, 'true') }}:
+    - task: PublishPipelineArtifact@0
+      displayName: 'Publish Artifact: layout_full_freethreaded_$(Name)'
+      inputs:
+        targetPath: '$(Build.ArtifactStagingDirectory)\layout_freethreaded'
+        artifactName: layout_full_freethreaded_$(Name)
diff --git a/windows-release/stage-layout-nuget.yml b/windows-release/stage-layout-nuget.yml
index b60a324d..215c0fb6 100644
--- a/windows-release/stage-layout-nuget.yml
+++ b/windows-release/stage-layout-nuget.yml
@@ -1,3 +1,6 @@
+parameters:
+  DoFreethreaded: false
+
 jobs:
 - job: Make_Nuget_Layout
   displayName: Make Nuget layout
@@ -45,8 +48,20 @@ jobs:
       $(LayoutCmd) --copy "$(Build.ArtifactStagingDirectory)\nuget" --preset-nuget
     displayName: 'Generate nuget layout'
 
+  - ${{ if eq(parameters.DoFreethreaded, 'true') }}:
+    - powershell: |
+        $(LayoutCmd) --copy "$(Build.ArtifactStagingDirectory)\nuget_freethreaded" --preset-nuget --include-freethreaded
+      displayName: 'Generate freethreaded nuget layout'
+
   - task: PublishPipelineArtifact@0
     displayName: 'Publish Artifact: layout_nuget_$(Name)'
     inputs:
       targetPath: '$(Build.ArtifactStagingDirectory)\nuget'
       artifactName: layout_nuget_$(Name)
+
+  - ${{ if eq(parameters.DoFreethreaded, 'true') }}:
+    - task: PublishPipelineArtifact@0
+      displayName: 'Publish Artifact: layout_nuget_freethreaded_$(Name)'
+      inputs:
+        targetPath: '$(Build.ArtifactStagingDirectory)\nuget_freethreaded'
+        artifactName: layout_nuget_freethreaded_$(Name)
diff --git a/windows-release/stage-msi.yml b/windows-release/stage-msi.yml
index d4cf4c9b..0b6fa76c 100644
--- a/windows-release/stage-msi.yml
+++ b/windows-release/stage-msi.yml
@@ -1,15 +1,16 @@
 parameters:
   ARM64TclTk: true
+  DoFreethreaded: false
   SigningCertificate: ''
 
 jobs:
 - ${{ if parameters.SigningCertificate }}:
   - job: Make_Signed_MSI
     displayName: Make signed MSI
-  
+
     pool:
       vmImage: windows-2022
-  
+
     variables:
     - group: CPythonSign
     - name: ReleaseUri
@@ -18,10 +19,10 @@ jobs:
       value: https://www.python.org/ftp/python/{version}/{arch}{releasename}/{msi}
     - name: Py_OutDir
       value: $(Build.BinariesDirectory)
-  
+
     workspace:
       clean: all
-  
+
     steps:
     - template: msi-steps.yml
       parameters:
@@ -32,19 +33,20 @@ jobs:
 - ${{ else }}:
   - job: Make_MSI
     displayName: Make MSI
-  
+
     pool:
       vmImage: windows-2022
-  
+
     variables:
       ReleaseUri: http://www.python.org/{arch}
       DownloadUrl: https://www.python.org/ftp/python/{version}/{arch}{releasename}/{msi}
       Py_OutDir: $(Build.BinariesDirectory)
-  
+
     workspace:
       clean: all
-  
+
     steps:
     - template: msi-steps.yml
       parameters:
         ARM64TclTk: ${{ parameters.ARM64TclTk }}
+        DoFreethreaded: ${{ parameters.DoFreethreaded }}
diff --git a/windows-release/stage-pack-nuget.yml b/windows-release/stage-pack-nuget.yml
index 2b4721da..ded8ce6c 100644
--- a/windows-release/stage-pack-nuget.yml
+++ b/windows-release/stage-pack-nuget.yml
@@ -1,4 +1,5 @@
 parameters:
+  DoFreethreaded: false
   SigningCertificate: ''
 
 jobs:
@@ -34,6 +35,13 @@ jobs:
       artifactName: layout_nuget_$(Name)
       targetPath: $(Build.BinariesDirectory)\layout
 
+  - ${{ if eq(parameters.DoFreethreaded, 'true') }}:
+    - task: DownloadPipelineArtifact@1
+      displayName: 'Download artifact: layout_nuget_freethreaded_$(Name)'
+      inputs:
+        artifactName: layout_nuget_freethreaded_$(Name)
+        targetPath: $(Build.BinariesDirectory)\layout_freethreaded
+
   - task: NugetToolInstaller@0
     displayName: 'Install Nuget'
     inputs:
@@ -58,6 +66,26 @@ jobs:
     condition: and(succeeded(), variables['OverrideNugetVersion'])
     displayName: 'Create nuget package'
 
+  - ${{ if eq(parameters.DoFreethreaded, 'true') }}:
+    - powershell: >
+        nuget pack
+        "$(Build.BinariesDirectory)\layout_freethreaded\python.nuspec"
+        -OutputDirectory $(Build.ArtifactStagingDirectory)
+        -NoPackageAnalysis
+        -NonInteractive
+      condition: and(succeeded(), not(variables['OverrideNugetVersion']))
+      displayName: 'Create freethreaded nuget package'
+
+    - powershell: >
+        nuget pack
+        "$(Build.BinariesDirectory)\layout_freethreaded\python.nuspec"
+        -OutputDirectory $(Build.ArtifactStagingDirectory)
+        -NoPackageAnalysis
+        -NonInteractive
+        -Version "$(OverrideNugetVersion)"
+      condition: and(succeeded(), variables['OverrideNugetVersion'])
+      displayName: 'Create freethreaded nuget package'
+
   - template: sign-nuget-files.yml
     parameters:
       Include: '*.nupkg'
diff --git a/windows-release/stage-test-msi.yml b/windows-release/stage-test-msi.yml
index 9aef742f..4f9f1009 100644
--- a/windows-release/stage-test-msi.yml
+++ b/windows-release/stage-test-msi.yml
@@ -1,3 +1,6 @@
+parameters:
+  DoFreethreaded: false
+
 jobs:
 - job: Test_MSI
   displayName: Test MSI
@@ -8,6 +11,12 @@ jobs:
   workspace:
     clean: all
 
+  variables:
+    ${{ if eq(parameters.DoFreethreaded, 'true') }}:
+      IncludeFreethreadedOpt: Include_freethreaded=1
+    ${{ else }}:
+      IncludeFreethreadedOpt: ''
+
   strategy:
     matrix:
       win32_User:
@@ -51,8 +60,13 @@ jobs:
       Include_debug=1
       Include_symbols=1
       InstallAllUsers=$(InstallAllUsers)
+      $(IncludeFreethreadedOpt)
     displayName: 'Install Python'
 
+  - powershell: |
+      gci "$(Build.BinariesDirectory)\python"
+    displayName: 'List installed files'
+
   - powershell: |
       $p = gi "$(Build.BinariesDirectory)\Python\python.exe"
       Write-Host "##vso[task.prependpath]$(Split-Path -Parent $p)"
@@ -68,6 +82,14 @@ jobs:
     displayName: 'Collect site'
     condition: and(succeeded(), not(variables['SkipTests']))
 
+  - ${{ if eq(parameters.DoFreethreaded, 'true') }}:
+    - powershell: |
+        $p = (gci "$(Build.BinariesDirectory)\Python\python3*t.exe" | select -First 1)
+        Write-Host "Found $p"
+        & $p -c "import sys; print(sys.version)"
+      displayName: 'Collect free-threaded version number'
+      condition: and(succeeded(), not(variables['SkipTests']))
+
   - powershell: |
       gci -r "${env:PROGRAMDATA}\Microsoft\Windows\Start Menu\Programs\Python*"
     displayName: 'Capture per-machine Start Menu items'