diff --git a/.github/workflows/build_package.yml b/.github/workflows/build_package.yml
index 1dfa2fd..97ac2a4 100644
--- a/.github/workflows/build_package.yml
+++ b/.github/workflows/build_package.yml
@@ -1,12 +1,16 @@
-# Builds packages for native (non cross-compiled) targets on supported
-# platforms.
-#
-# For these mainline distributions, we use cibuildwheel and drive the
-# packaging through python, extracting native assets. While this may seem
-# hopelessly round-about, it lets us leverage a lot of what cibuildwheel
-# does for free and get python packages to boot.
-name: Build Native Release Packages
+# Builds release packages on supported platforms:
+#   * main-dist-linux (CMake 'install')
+#   * py-compiler-pkg (`iree-compiler` Python package)
+#     * Linux, macOS, Windows
+#     * All supported Python versions (e.g. 3.8, 3.9, 3.10, 3.11)
+#   * py-runtime-pkg (`iree-runtime[-instrumented]` Python package)
+#     * Linux, macOS, Windows
+#     * All supported Python versions (e.g. 3.8, 3.9, 3.10, 3.11)
+#   * py-tf-compiler-tools-pkg (`iree-tools-[tf, tflite]`, pure Python packages)
 
+name: Build Release Packages
+
+# Note: this workflow is typically invoked by schedule_candidate_release.yml.
 on:
   workflow_dispatch:
     inputs:
@@ -26,7 +30,7 @@
         default: ""
 
 jobs:
-  build_core:
+  build_packages:
     name: "${{ matrix.build-family }} :: Build ${{ matrix.build-package }} Package"
     runs-on: ${{ matrix.runs-on }}
     continue-on-error: ${{ matrix.experimental }}
@@ -67,13 +71,25 @@
             build-family: macos
             build-package: py-runtime-pkg
             experimental: true
+
+          # Windows packages.
+          - runs-on:
+              - ${{ github.repository == 'openxla/iree' && 'windows-2022-64core' || 'windows-2022'}}
+            build-family: windows
+            build-package: py-compiler-pkg
+            experimental: true
+          - runs-on: windows-2022
+            build-family: windows
+            build-package: py-runtime-pkg
+            experimental: true
+
     env:
       MANYLINUX_X86_64_IMAGE: gcr.io/iree-oss/manylinux2014_x86_64-release@sha256:e83893d35be4ce3558c989e9d5ccc4ff88d058bc3e74a83181059cc76e2cf1f8
 
     steps:
       - uses: actions/checkout@8f4b7f84864484a7bf31766abe9204da3cbe65b3 # v3.5.0
         with:
-          path: "main_checkout"
+          path: "c"  # Windows can hit path length limits, so use a short path.
           submodules: true
           ref: ${{ github.event.inputs.commit }}
 
@@ -81,6 +97,14 @@
       # OS specific setup
       ##########################################################################
 
+      - name: Install dependencies (Windows)
+        if: "matrix.build-family == 'windows'"
+        shell: powershell
+        run: ./c/build_tools/python_deploy/install_windows_deps.ps1
+      - name: "Configure MSVC (Windows)"
+        if: "matrix.build-family == 'windows'"
+        uses: ilammy/msvc-dev-cmd@7315a94840631165970262a99c72cfb48a65d25d # v1.12.0
+
       ##########################################################################
       # Write version_info.json
       # Various tools will read this in order to embed release information.
@@ -88,14 +112,14 @@
       - name: Write version info (release)
         shell: bash
         run: |
-          cat << EOF > ./main_checkout/version_info.json
+          cat << EOF > ./c/version_info.json
           {
             "package-suffix": "${{ github.event.inputs.package_suffix }}",
             "package-version": "${{ github.event.inputs.package_version }}",
-            "iree-revision": "$(cd ./main_checkout && git rev-parse HEAD)"
+            "iree-revision": "$(cd ./c && git rev-parse HEAD)"
           }
           EOF
-          cat ./main_checkout/version_info.json
+          cat ./c/version_info.json
 
       ##########################################################################
       # Build the main distribution tarball.
@@ -116,7 +140,7 @@
           docker run --rm -w=/work \
             -v $PWD:/work \
             "${MANYLINUX_X86_64_IMAGE}" \
-            bash -c 'export PATH=/opt/python/cp39-cp39/bin:$PATH; python ./main_checkout/build_tools/github_actions/build_dist.py main-dist'
+            bash -c 'export PATH=/opt/python/cp39-cp39/bin:$PATH; python ./c/build_tools/github_actions/build_dist.py main-dist'
 
       ##########################################################################
       # py-runtime-pkg
@@ -132,7 +156,7 @@
           packages: "iree-runtime iree-runtime-instrumented"
           output_dir: "${{ github.workspace }}/bindist"
         run: |
-          ./main_checkout/build_tools/python_deploy/build_linux_packages.sh
+          ./c/build_tools/python_deploy/build_linux_packages.sh
 
       - name: Build runtime wheels (MacOS)
         if: "matrix.build-package == 'py-runtime-pkg' && matrix.build-family == 'macos'"
@@ -143,11 +167,22 @@
           output_dir: "${{ github.workspace }}/bindist"
           override_python_versions: "3.11"
         run: |
-          ./main_checkout/build_tools/python_deploy/build_macos_packages.sh
+          ./c/build_tools/python_deploy/build_macos_packages.sh
+
+      - name: Build runtime wheels (Windows)
+        if: "matrix.build-package == 'py-runtime-pkg' && matrix.build-family == 'windows'"
+        shell: bash
+        env:
+          package_suffix: ${{ github.event.inputs.package_suffix }}
+          packages: "iree-runtime iree-runtime-instrumented"
+          output_dir: "${{ github.workspace }}/bindist"
+          override_python_versions: "3.11"
+        run: |
+          ./c/build_tools/python_deploy/build_windows_packages.sh
 
       ##########################################################################
       # py-compiler-pkg
-      # Builds the iree-compielr wheel.
+      # Builds the iree-compiler wheel.
       # One step per OS.
       ##########################################################################
       - name: Build compiler wheels (Linux)
@@ -158,7 +193,7 @@
           packages: "iree-compiler"
           output_dir: "${{ github.workspace }}/bindist"
         run: |
-          ./main_checkout/build_tools/python_deploy/build_linux_packages.sh
+          ./c/build_tools/python_deploy/build_linux_packages.sh
 
       - name: Build compiler wheels (MacOS)
         if: "matrix.build-package == 'py-compiler-pkg' && matrix.build-family == 'macos'"
@@ -169,13 +204,23 @@
           output_dir: "${{ github.workspace }}/bindist"
           override_python_versions: "3.11"
         run: |
-          ./main_checkout/build_tools/python_deploy/build_macos_packages.sh
+          ./c/build_tools/python_deploy/build_macos_packages.sh
+
+      - name: Build compiler wheels (Windows)
+        if: "matrix.build-package == 'py-compiler-pkg' && matrix.build-family == 'windows'"
+        shell: bash
+        env:
+          package_suffix: ${{ github.event.inputs.package_suffix }}
+          packages: "iree-compiler"
+          output_dir: "${{ github.workspace }}/bindist"
+          override_python_versions: "3.11"
+        run: |
+          ./c/build_tools/python_deploy/build_windows_packages.sh
 
       ##########################################################################
       # TF Compiler Tools
-      # Compiler tools wheels are not python version specific, so just build
-      # for one examplar python version.
-      # TODO: This currently only builds on Linux and is hardcoded to do so.
+      # These wheels are not Python version specific and include only Python
+      # code (no C/C++), so just build for one examplar python version on Linux.
       ##########################################################################
 
       - name: Build TF Compiler Tools wheels
@@ -185,7 +230,7 @@
           docker run --rm -w=/work \
             -v $PWD:/work \
             "${MANYLINUX_X86_64_IMAGE}" \
-            bash -c 'export PATH=/opt/python/cp39-cp39/bin:$PATH; python ./main_checkout/build_tools/github_actions/build_dist.py py-tf-compiler-tools-pkg'
+            bash -c 'export PATH=/opt/python/cp39-cp39/bin:$PATH; python ./c/build_tools/github_actions/build_dist.py py-tf-compiler-tools-pkg'
 
       - uses: actions/upload-artifact@0b7f8abb1508181956e8e162db84b466c27e18ce # v3.1.2
         with:
@@ -207,8 +252,8 @@
           assets_path: ./bindist/iree*.*
 
   validate_and_publish:
-    name: "Invoke workflow to validate and publish release"
-    needs: build_core
+    name: "Trigger validate and publish release"
+    needs: build_packages
     if: github.event.inputs.release_id != ''
     runs-on: ubuntu-20.04
     steps:
diff --git a/build_tools/github_actions/build_dist.py b/build_tools/github_actions/build_dist.py
index 19dbcc6..be49b60 100644
--- a/build_tools/github_actions/build_dist.py
+++ b/build_tools/github_actions/build_dist.py
@@ -17,9 +17,9 @@
 
 This is expected to be run from the project directory, containing the
 following sub-directories:
-  - main_checkout/ : Main IREE repository checkout.
+  - c/ : Main IREE repository checkout.
   - bindist/ : Directory where binary distribution artifacts are written.
-  - main_checkout/version_info.json : Version config information.
+  - c/version_info.json : Version config information.
 
 Within the build environment (which may be the naked runner or a docker image):
   - iree-build/ : The build tree.
@@ -33,13 +33,13 @@
 It is not recommended to run cibuildwheel locally. However, this script can
 be executed as if running within such an environment. To do so, create
 a directory and:
-  ln -s /path/to/iree main_checkout
+  ln -s /path/to/iree c
   python -m venv .venv
   source .venv/bin/activate
 
-  python ./main_checkout/build_tools/github_actions/build_dist.py main-dist
-  python ./main_checkout/build_tools/github_actions/build_dist.py py-tflite-compiler-tools-pkg
-  python ./main_checkout/build_tools/github_actions/build_dist.py py-tf-compiler-tools-pkg
+  python ./c/build_tools/github_actions/build_dist.py main-dist
+  python ./c/build_tools/github_actions/build_dist.py py-tflite-compiler-tools-pkg
+  python ./c/build_tools/github_actions/build_dist.py py-tf-compiler-tools-pkg
 
 
 That is not a perfect approximation but is close.
@@ -58,7 +58,7 @@
 WORK_DIR = os.path.realpath(os.path.curdir)
 BUILD_DIR = os.path.join(WORK_DIR, "iree-build")
 INSTALL_DIR = os.path.join(WORK_DIR, "iree-install")
-IREESRC_DIR = os.path.join(WORK_DIR, "main_checkout")
+IREESRC_DIR = os.path.join(WORK_DIR, "c")
 TF_INTEGRATIONS_DIR = os.path.join(IREESRC_DIR, "integrations/tensorflow")
 BINDIST_DIR = os.environ.get("BINDIST_DIR")
 if BINDIST_DIR is None:
@@ -184,7 +184,7 @@
 
 
 def build_py_tf_compiler_tools_pkg():
-    """Builds the iree-install/python_packages/iree_tools_tf package."""
+    """Builds iree-install/python_packages/iree_tools_[tf, tflite] packages."""
     install_python_requirements()
     configure_bazel()
 
diff --git a/build_tools/python_deploy/build_windows_packages.sh b/build_tools/python_deploy/build_windows_packages.sh
new file mode 100644
index 0000000..7cc1d7a
--- /dev/null
+++ b/build_tools/python_deploy/build_windows_packages.sh
@@ -0,0 +1,97 @@
+#!/bin/bash
+# Copyright 2023 The IREE Authors
+#
+# Licensed under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+# build_windows_packages.sh
+# One stop build of IREE Python packages for Windows. This presumes that
+# dependencies are installed from install_windows_deps.ps1.
+#
+# Valid packages:
+#   iree-runtime
+#   iree-runtime-instrumented
+#   iree-compiler
+
+set -eu -o errtrace
+
+this_dir="$(cd $(dirname $0) && pwd)"
+repo_root="$(cd $this_dir/../../ && pwd)"
+python_versions="${override_python_versions:-3.11}"
+output_dir="${output_dir:-${this_dir}/wheelhouse}"
+packages="${packages:-iree-runtime iree-runtime-instrumented iree-compiler}"
+
+# Canonicalize paths.
+mkdir -p "$output_dir"
+output_dir="$(cd $output_dir && pwd)"
+
+function run() {
+  echo "Using python versions: ${python_versions}"
+
+  local orig_path="$PATH"
+
+  # Build phase.
+  for package in $packages; do
+    echo "******************** BUILDING PACKAGE ${package} ********************"
+    for python_version in $python_versions; do
+      if [[ $(py --list) != *${python_version}* ]]; then
+        echo "ERROR: Could not find python version: ${python_version}"
+        continue
+      fi
+
+      echo ":::: Version: $(py -${python_version} --version)"
+      case "$package" in
+        iree-runtime)
+          clean_wheels iree_runtime $python_version
+          build_iree_runtime $python_version
+          ;;
+        iree-runtime-instrumented)
+          clean_wheels iree_runtime_instrumented $python_version
+          build_iree_runtime_instrumented $python_version
+          ;;
+        iree-compiler)
+          clean_wheels iree_compiler $python_version
+          build_iree_compiler $python_version
+          ;;
+        *)
+          echo "Unrecognized package '$package'"
+          exit 1
+          ;;
+      esac
+    done
+  done
+
+  echo "******************** BUILD COMPLETE ********************"
+  echo "Generated binaries:"
+  ls -l $output_dir
+}
+
+function build_iree_runtime() {
+  local python_version="$1"
+  IREE_HAL_DRIVER_VULKAN=ON \
+  py -${python_version} -m pip wheel -v -w $output_dir $repo_root/runtime/
+}
+
+function build_iree_runtime_instrumented() {
+  local python_version="$1"
+  IREE_HAL_DRIVER_VULKAN=ON IREE_ENABLE_RUNTIME_TRACING=ON \
+  IREE_RUNTIME_CUSTOM_PACKAGE_SUFFIX="-instrumented" \
+  py -${python_version} -m pip wheel -v -w $output_dir $repo_root/runtime/
+}
+
+function build_iree_compiler() {
+  local python_version="$1"
+  py -${python_version} -m pip wheel -v -w $output_dir $repo_root/compiler/
+}
+
+function clean_wheels() {
+  local wheel_basename="$1"
+  local python_version="$2"
+  echo ":::: Clean wheels $wheel_basename $python_version"
+  # python_version is something like "3.11", but we'd want something like "cp311".
+  local cpython_version_string="cp${python_version%.*}${python_version#*.}"
+  rm -f -v ${output_dir}/${wheel_basename}-*-${cpython_version_string}-*.whl
+}
+
+run
diff --git a/build_tools/python_deploy/install_macos_deps.sh b/build_tools/python_deploy/install_macos_deps.sh
index 9e01333..ec51cde 100755
--- a/build_tools/python_deploy/install_macos_deps.sh
+++ b/build_tools/python_deploy/install_macos_deps.sh
@@ -18,19 +18,13 @@
   exit 1
 fi
 
-PYTHON_INSTALLER_URLS=(
-  "https://www.python.org/ftp/python/3.11.2/python-3.11.2-macos11.pkg"
-  "https://www.python.org/ftp/python/3.10.10/python-3.10.10-macos11.pkg"
-  "https://www.python.org/ftp/python/3.9.13/python-3.9.13-macos11.pkg"
-)
-
 PYTHON_SPECS=(
   3.11@https://www.python.org/ftp/python/3.11.2/python-3.11.2-macos11.pkg
   3.10@https://www.python.org/ftp/python/3.10.5/python-3.10.5-macos11.pkg
   3.9@https://www.python.org/ftp/python/3.9.13/python-3.9.13-macos11.pkg
 )
 
-for python_spec in $PYTHON_SPECS; do
+for python_spec in "${PYTHON_SPECS[@]}"; do
   python_version="${python_spec%%@*}"
   url="${python_spec##*@}"
   echo "-- Installing Python $python_version from $url"
diff --git a/build_tools/python_deploy/install_windows_deps.ps1 b/build_tools/python_deploy/install_windows_deps.ps1
new file mode 100644
index 0000000..c3d9187
--- /dev/null
+++ b/build_tools/python_deploy/install_windows_deps.ps1
@@ -0,0 +1,67 @@
+# Copyright 2023 The IREE Authors
+#
+# Licensed under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+# Installs dependencies on Windows necessary to build IREE Python wheels.
+
+$PYTHON_VERSIONS = @(
+  "3.11" #,
+  # "3.10",
+  # "3.9"
+)
+
+$PYTHON_VERSIONS_NO_DOT = @(
+  "311" #,
+  # "310",
+  # "39"
+)
+
+$PYTHON_INSTALLER_URLS = @(
+  "https://www.python.org/ftp/python/3.11.2/python-3.11.2-amd64.exe" #,
+  # "https://www.python.org/ftp/python/3.10.5/python-3.10.5-amd64.exe",
+  # "https://www.python.org/ftp/python/3.9.13/python-3.9.13-amd64.exe"
+)
+
+# Multiple Python install locations are valid, so we use the `py` helper to
+# check for versions and call into them. Some valid install locations are:
+#   C:\Python39\python.exe
+#   C:\Program Files\Python39\python.exe
+#   C:\Users\[NAME]\AppData\Local\Programs\Python\Python39\python.exe
+# See https://docs.python.org/3/using/windows.html#python-launcher-for-windows.
+$INSTALLED_VERSIONS_OUTPUT = py --list | Out-String
+
+for($i=0 ; $i -lt $PYTHON_VERSIONS.Length; $i++) {
+  $PYTHON_VERSION = $PYTHON_VERSIONS[$i]
+  $PYTHON_VERSION_NO_DOT = $PYTHON_VERSIONS_NO_DOT[$i]
+  $PYTHON_INSTALLER_URL = $PYTHON_INSTALLER_URLS[$i]
+  Write-Host "-- Installing Python ${PYTHON_VERSION} from ${PYTHON_INSTALLER_URL}"
+
+  if ("${INSTALLED_VERSIONS_OUTPUT}" -like "*${PYTHON_VERSION}*") {
+    Write-Host "::  Python version already installed. Not reinstalling."
+  } else {
+    $DOWNLOAD_ROOT = "$env:TEMP/iree_python_install"
+    $DOWNLOAD_FILENAME = $PYTHON_INSTALLER_URL.Substring($PYTHON_INSTALLER_URL.LastIndexOf("/") + 1)
+    $DOWNLOAD_PATH = "${DOWNLOAD_ROOT}/$DOWNLOAD_FILENAME"
+
+    # Create download folder as needed.
+    md -Force ${DOWNLOAD_ROOT} | Out-Null
+
+    Write-Host "::  Downloading $PYTHON_INSTALLER_URL -> $DOWNLOAD_PATH"
+    curl $PYTHON_INSTALLER_URL -o $DOWNLOAD_PATH
+
+    Write-Host "::  Running installer: $DOWNLOAD_PATH"
+    # https://docs.python.org/3/using/windows.html#installing-without-ui
+    & "$DOWNLOAD_PATH" /quiet InstallAllUsers=1 PrependPath=1 Include_test=0
+  }
+
+  Write-Host "::  Python version $PYTHON_VERSION installed:"
+  & py -${PYTHON_VERSION} --version
+  & py -${PYTHON_VERSION} -m pip --version
+
+  Write-Host "::  Installing system pip packages"
+  & py -${PYTHON_VERSION} -m pip install --upgrade pip
+}
+
+Write-Host "*** All done ***"
diff --git a/compiler/setup.py b/compiler/setup.py
index 5a7f41e..eab5112 100644
--- a/compiler/setup.py
+++ b/compiler/setup.py
@@ -75,8 +75,10 @@
 # We must do the intermediate installation to a fixed location that agrees
 # between what we pass to setup() and cmake. So hard-code it here.
 # Note that setup() needs a relative path (to the setup.py file).
+# We keep the path short ('i' instead of 'install') for platforms like Windows
+# that have file length limits.
 SETUPPY_DIR = os.path.realpath(os.path.dirname(__file__))
-CMAKE_INSTALL_DIR_REL = os.path.join("build", "cmake_install")
+CMAKE_INSTALL_DIR_REL = os.path.join("build", "i")
 CMAKE_INSTALL_DIR_ABS = os.path.join(SETUPPY_DIR, CMAKE_INSTALL_DIR_REL)
 
 IS_CONFIGURED = CONFIGURED_SOURCE_DIR[0] != "@"
@@ -96,7 +98,7 @@
         # Note that setuptools always builds into a "build" directory that
         # is a sibling of setup.py, so we just colonize a sub-directory of that
         # by default.
-        IREE_BINARY_DIR = os.path.join(SETUPPY_DIR, "build", "cmake_build")
+        IREE_BINARY_DIR = os.path.join(SETUPPY_DIR, "build", "b")
     print(
         f"Running setup.py from source tree: "
         f"SOURCE_DIR = {IREE_SOURCE_DIR} "
diff --git a/docs/developers/debugging/releases.md b/docs/developers/debugging/releases.md
index 2b4a15b..3142ed9 100644
--- a/docs/developers/debugging/releases.md
+++ b/docs/developers/debugging/releases.md
@@ -5,9 +5,9 @@
 * `.github/workflows/build_package.yml`: Release packaging jobs
 * `build_tools/github_actions/build_dist.py`: Main script to build various
   release packages (for all platforms). We usually use this when reproing to
-  approximate exactly what the CI does. Assumes a subdirectory of `main_checkout`
+  approximate exactly what the CI does. Assumes a subdirectory of `c`
   and writes builds to `iree-build` and `iree-install` as a peer of it. To use
-  locally, just symlink your source dir as `main_checkout` in an empty
+  locally, just symlink your source dir as `c` in an empty
   directory (versus checking out).
 
 ## Manylinux releases
@@ -21,11 +21,11 @@
 Get a docker shell (see exact docker image in build_package.yml workflow):
 
 ```shell
-docker run --rm -it -v $(pwd):/work/main_checkout stellaraccident/manylinux2014_x86_64-bazel-4.2.2:latest /bin/bash
+docker run --rm -it -v $(pwd):/work/c stellaraccident/manylinux2014_x86_64-bazel-4.2.2:latest /bin/bash
 ```
 
 Remember that docker runs as root unless if you take steps otherwise. Don't
-touch write files in the `/work/main_checkout` directory to avoid scattering
+touch write files in the `/work/c` directory to avoid scattering
 root owned files on your workstation.
 
 The default system Python is 2.x, so you must select one of the more modern
@@ -41,7 +41,7 @@
 ```shell
 # (from within docker)
 cd /work
-python ./main_checkout/build_tools/github_actions/build_dist.py main-dist
+python ./c/build_tools/github_actions/build_dist.py main-dist
 
 # Also supports:
 #   main-dist
diff --git a/runtime/setup.py b/runtime/setup.py
index f5077f9..c3eb7ed 100644
--- a/runtime/setup.py
+++ b/runtime/setup.py
@@ -79,8 +79,10 @@
 # We must do the intermediate installation to a fixed location that agrees
 # between what we pass to setup() and cmake. So hard-code it here.
 # Note that setup() needs a relative path (to the setup.py file).
+# We keep the path short ('i' instead of 'install') for platforms like Windows
+# that have file length limits.
 SETUPPY_DIR = os.path.realpath(os.path.dirname(__file__))
-CMAKE_INSTALL_DIR_REL = os.path.join("build", "cmake_install")
+CMAKE_INSTALL_DIR_REL = os.path.join("build", "i")
 CMAKE_INSTALL_DIR_ABS = os.path.join(SETUPPY_DIR, CMAKE_INSTALL_DIR_REL)
 
 IS_CONFIGURED = CONFIGURED_SOURCE_DIR[0] != "@"
@@ -100,7 +102,7 @@
         # Note that setuptools always builds into a "build" directory that
         # is a sibling of setup.py, so we just colonize a sub-directory of that
         # by default.
-        IREE_BINARY_DIR = os.path.join(SETUPPY_DIR, "build", "cmake_build")
+        IREE_BINARY_DIR = os.path.join(SETUPPY_DIR, "build", "b")
     print(
         f"Running setup.py from source tree: "
         f"SOURCE_DIR = {IREE_SOURCE_DIR} "