diff --git a/3rdparty/Makefile b/3rdparty/Makefile
index 537f9811..366cf142 100644
--- a/3rdparty/Makefile
+++ b/3rdparty/Makefile
@@ -14,6 +14,8 @@ NC := \033[0m
 # Optional audiofile: only the legacy `audiofile-patched/` tree (from zip), not the
 # submodule path, so default Windows deps stay minimal and build with current GCC.
 AUDIOFILE_SRC := $(shell if [ -d "audiofile-patched" ]; then echo "audiofile-patched"; else echo ""; fi)
+HOST_CONFIGURE_ARG := $(if $(MACOS_MINGW_CROSS),--host=$(MINGW_HOST),)
+CMAKE_CROSS_ARGS := $(if $(MACOS_MINGW_CROSS),-DCMAKE_SYSTEM_NAME=Windows -DCMAKE_C_COMPILER=$(CC),)
 
 .PHONY: all clean distclean libspectrum audiofile libxml2 mbedtls libssh2 check-tools check-libspectrum check-libssh2 extract-audiofile extract-libxml2 libspectrum-with-audiofile
 
@@ -100,7 +102,7 @@ libspectrum: dist-dirs check-libspectrum
 	if [ ! -f configure ]; then \
 		./autogen.sh; \
 	fi && \
-	./configure --with-fake-glib --without-libaudiofile --without-libgcrypt \
+	./configure $(HOST_CONFIGURE_ARG) --with-fake-glib --without-libaudiofile --without-libgcrypt \
 	            --without-zlib --without-bzip2 --prefix="$(DIST_PREFIX)" && \
 	$(MAKE) && \
 	$(MAKE) install
@@ -181,6 +183,7 @@ libssh2: mbedtls dist-dirs check-libssh2
 		cd libssh2/src/build && \
 		cmake .. \
 			-G "Unix Makefiles" \
+			$(CMAKE_CROSS_ARGS) \
 			-DCMAKE_INSTALL_PREFIX="$(DIST_PREFIX)" \
 			-DCMAKE_BUILD_TYPE=Release \
 			-DBUILD_SHARED_LIBS=OFF \
diff --git a/Makefile b/Makefile
index f14fee4b..d9b80ae5 100644
--- a/Makefile
+++ b/Makefile
@@ -174,9 +174,6 @@ archive: 3rdparty fusepb
 		-scheme FuseX \
 		-configuration Deployment \
 		-archivePath "$(CURDIR)/$(ARCHIVE_PATH)" \
-		SYMROOT=build \
-		BUILD_DIR=build \
-		CONFIGURATION_BUILD_DIR=build/Deployment \
 			$(XCODEBUILD_SIGN_ARGS)
 	@echo "Archive created at: $(ARCHIVE_PATH)"
 
diff --git a/build_win32.sh b/build_win32.sh
index 3d22fdc8..24b93d73 100644
--- a/build_win32.sh
+++ b/build_win32.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
-# FuseX — Windows distribution build (MSYS2 MinGW 64-bit).
-# Prerequisite: MSYS2 with mingw-w64-x86_64 toolchain, perl, zip, 7zip (optional), NSIS (optional).
+# FuseX — Windows distribution build (MSYS2 or a macOS MinGW cross-toolchain).
+# Prerequisite: MinGW-w64, perl, zip, 7zip (optional), NSIS (optional).
 
 set -e
 
@@ -11,18 +11,39 @@ GREEN='\033[0;32m'
 YELLOW='\033[1;33m'
 NC='\033[0m'
 
-if [[ -z "${MSYSTEM:-}" ]]; then
-    echo -e "${RED}Error: run this from MSYS2 (e.g. \"MSYS2 MinGW 64-bit\"), not plain PowerShell.${NC}"
+HOST_OS="$(uname -s)"
+if [[ "$HOST_OS" == "Darwin" ]]; then
+    MACOS_MINGW_CROSS=1
+    export MACOS_MINGW_CROSS
+    MINGW_HOST="${MINGW_HOST:-x86_64-w64-mingw32}"
+    export MINGW_HOST
+    export CC="${MINGW_CC:-${MINGW_HOST}-gcc}"
+    export CXX="${MINGW_CXX:-${MINGW_HOST}-g++}"
+    export AR="${MINGW_AR:-${MINGW_HOST}-ar}"
+    export RANLIB="${MINGW_RANLIB:-${MINGW_HOST}-ranlib}"
+    export STRIP="${MINGW_STRIP:-${MINGW_HOST}-strip}"
+    export WINDRES="${MINGW_WINDRES:-${MINGW_HOST}-windres}"
+    echo -e "${GREEN}Using macOS MinGW cross-toolchain: ${MINGW_HOST}${NC}"
+elif [[ -z "${MSYSTEM:-}" ]]; then
+    echo -e "${RED}Error: run this from MSYS2 or from macOS with MinGW-w64 installed.${NC}"
     exit 1
-fi
-
-if [[ "$MSYSTEM" != "MINGW64" && "$MSYSTEM" != "UCRT64" ]]; then
+elif [[ "$MSYSTEM" != "MINGW64" && "$MSYSTEM" != "UCRT64" ]]; then
     echo -e "${YELLOW}Warning: MINGW64 or UCRT64 is recommended (current: $MSYSTEM).${NC}"
 fi
 
 SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 cd "$SCRIPT_DIR"
 
+if [[ "$HOST_OS" == "Darwin" ]]; then
+    # Homebrew users often export native include/library flags globally. Those
+    # paths must not enter Windows objects during a cross-build.
+    export CFLAGS="${MINGW_CFLAGS:-}"
+    export CPPFLAGS="${MINGW_CPPFLAGS:-}"
+    export LDFLAGS="${MINGW_LDFLAGS:-}"
+    export PKG_CONFIG_PATH="$SCRIPT_DIR/3rdparty/dist/lib/pkgconfig"
+    export PKG_CONFIG_LIBDIR="$PKG_CONFIG_PATH"
+fi
+
 # Windows NSIS installs makensis.exe here but does not add it to MSYS PATH — match typical fuse dev setups.
 for _nsis in "/c/Program Files/NSIS" "/c/Program Files (x86)/NSIS"; do
   if [[ -d "$_nsis" ]] && [[ -x "$_nsis/makensis.exe" || -x "$_nsis/makensis" ]]; then
@@ -32,24 +53,42 @@ for _nsis in "/c/Program Files/NSIS" "/c/Program Files (x86)/NSIS"; do
   fi
 done
 
+if [[ "$HOST_OS" == "Darwin" ]]; then
+    export MINGW_RUNTIME_DIR="${MINGW_RUNTIME_DIR:-$($CC -print-sysroot)/${MINGW_HOST}/bin}"
+fi
+
 # Code generators assume Unix line endings on option/menu data (avoid CRLF breakage under Windows).
 for f in ui/options.dat menu_data.dat settings.dat keysyms.dat \
          z80/opcodes_base.dat z80/opcodes_cb.dat z80/opcodes_ddfd.dat \
          z80/opcodes_ddfdcb.dat z80/opcodes_ed.dat; do
   if [[ -f "$f" ]]; then
-    sed -i 's/\r$//' "$f" 2>/dev/null || true
+    if [[ "$HOST_OS" == "Darwin" ]]; then
+      perl -pi -e 's/\r$//' "$f"
+    else
+      sed -i 's/\r$//' "$f" 2>/dev/null || true
+    fi
   fi
 done
 
 echo -e "${GREEN}Directory: $SCRIPT_DIR${NC}"
 
 echo -e "\n${GREEN}Checking tools...${NC}"
-for tool in gcc make pkg-config perl; do
+TOOLS=( gcc make pkg-config perl )
+if [[ "$HOST_OS" == "Darwin" ]]; then
+    TOOLS=( "$CC" make pkg-config perl )
+fi
+for tool in "${TOOLS[@]}"; do
     if ! command -v "$tool" &> /dev/null; then
         echo -e "${RED}Missing: $tool${NC}"
         case "$tool" in
           perl) echo "  pacman -S mingw-w64-x86_64-perl" ;;
-          *) echo "  pacman -S mingw-w64-x86_64-$tool" ;;
+          *)
+            if [[ "$HOST_OS" == "Darwin" ]]; then
+              echo "  Install the MinGW-w64 build tool containing: $tool"
+            else
+              echo "  pacman -S mingw-w64-x86_64-$tool"
+            fi
+            ;;
         esac
         exit 1
     fi
@@ -71,13 +110,22 @@ export PKG_CONFIG_PATH="$DIST_PREFIX/lib/pkgconfig:${PKG_CONFIG_PATH:-}"
 # Link the static archive explicitly (avoids picking /usr/local libspectrum.dll.a via libtool).
 PC="$DIST_PREFIX/lib/pkgconfig/libspectrum.pc"
 if [[ -f "$PC" ]]; then
-  sed -i 's|^Libs:.*|Libs: ${libdir}/libspectrum.a|' "$PC" 2>/dev/null || true
+  if [[ "$HOST_OS" == "Darwin" ]]; then
+    perl -pi -e 's|^Libs:.*|Libs: \${libdir}/libspectrum.a|' "$PC"
+  else
+    sed -i 's|^Libs:.*|Libs: ${libdir}/libspectrum.a|' "$PC" 2>/dev/null || true
+  fi
 fi
 
 # Static libspectrum from 3rdparty: strip dllimport so MinGW links the .a correctly.
 if [[ -f "$DIST_PREFIX/include/libspectrum.h" ]]; then
-  sed -i 's/#define LIBSPECTRUM_API __declspec( dllimport )/#define LIBSPECTRUM_API/g' \
-    "$DIST_PREFIX/include/libspectrum.h" 2>/dev/null || true
+  if [[ "$HOST_OS" == "Darwin" ]]; then
+    perl -pi -e 's/#define LIBSPECTRUM_API __declspec\( dllimport \)/#define LIBSPECTRUM_API/g' \
+      "$DIST_PREFIX/include/libspectrum.h"
+  else
+    sed -i 's/#define LIBSPECTRUM_API __declspec( dllimport )/#define LIBSPECTRUM_API/g' \
+      "$DIST_PREFIX/include/libspectrum.h" 2>/dev/null || true
+  fi
 fi
 # Prefer the static archive: libspectrum.dll.a can make -lspectrum import from a DLL.
 if [[ -f "$DIST_PREFIX/lib/libspectrum.a" && -f "$DIST_PREFIX/lib/libspectrum.dll.a" ]]; then
@@ -86,7 +134,11 @@ if [[ -f "$DIST_PREFIX/lib/libspectrum.a" && -f "$DIST_PREFIX/lib/libspectrum.dl
 fi
 
 echo -e "\n${GREEN}Generating configure if needed...${NC}"
-if [[ ! -f configure ]]; then
+if [[ "$HOST_OS" == "Darwin" ]]; then
+    # Building libspectrum refreshes the shared libtool support files in this
+    # source tree. Regenerate Fuse's configure files with that same version.
+    ./autogen.sh
+elif [[ ! -f configure ]]; then
     ./autogen.sh
 else
     echo "  configure present"
@@ -95,7 +147,18 @@ fi
 echo -e "\n${GREEN}Configuring FuseX...${NC}"
 
 # Sockets enabled (default): Spectranet, gdbserver remote, etc. require Winsock on Windows.
-CONFIGURE_OPTS=( --with-win32 --without-zlib --without-png --prefix=/usr/local )
+CONFIGURE_PREFIX="/usr/local"
+if [[ "$HOST_OS" == "Darwin" ]]; then
+    # Avoid an unrelated native /usr/local/include/libspectrum.h taking
+    # precedence over the Windows library built above.
+    CONFIGURE_PREFIX="$DIST_PREFIX"
+fi
+CONFIGURE_OPTS=( --with-win32 --without-zlib --without-png --prefix="$CONFIGURE_PREFIX" )
+if [[ "$HOST_OS" == "Darwin" ]]; then
+    CONFIGURE_OPTS=( --host="$MINGW_HOST" "${CONFIGURE_OPTS[@]}" )
+    # Never allow pkg-config to fall back to native macOS libraries.
+    export PKG_CONFIG_LIBDIR="$DIST_PREFIX/lib/pkgconfig"
+fi
 if pkg-config --exists libxml-2.0 2>/dev/null; then
     echo "  with libxml2 (pkg-config)"
 else
@@ -105,10 +168,18 @@ fi
 
 ./configure "${CONFIGURE_OPTS[@]}"
 
+if [[ "${WIN32_CLEAN:-0}" == "1" ]]; then
+    echo -e "\n${GREEN}Cleaning the configured Windows build...${NC}"
+    make clean
+fi
+
 echo -e "\n${GREEN}Building and creating Windows distribution (zip, 7z, installer if NSIS is available)...${NC}"
 # Same as upstream fuse build_win32.sh: one target builds zip + 7z + setup.exe (see data/win32/distribution.mk).
 if command -v makensis &>/dev/null || command -v makensis.exe &>/dev/null; then
-    make dist-win32 -j"$(nproc 2>/dev/null || echo 4)"
+    make "${WIN32_DIST_TARGET:-dist-win32}" -j"$(nproc 2>/dev/null || sysctl -n hw.ncpu 2>/dev/null || echo 4)"
+elif [[ "${REQUIRE_NSIS:-0}" == "1" ]]; then
+    echo -e "${RED}NSIS is required, but makensis was not found.${NC}"
+    exit 1
 else
     echo -e "${YELLOW}makensis not on PATH — building zip/7z only. Add NSIS to PATH or install to:${NC}"
     echo "  C:\\Program Files\\NSIS  or  C:\\Program Files (x86)\\NSIS"
@@ -133,7 +204,7 @@ if [[ -z "$SETUP_EXE" ]]; then
     SETUP_EXE="$( ls "$SCRIPT_DIR"/fusex-*-win32-setup.exe 2>/dev/null | sort -V | tail -1 )"
 fi
 APPCAST_SRC="$SCRIPT_DIR/build/appcast-windows/appcast.xml"
-if [[ -n "$SETUP_EXE" ]]; then
+if [[ -n "$SETUP_EXE" && "${SKIP_APPCAST:-0}" != "1" ]]; then
     echo -e "\n${GREEN}Generating WinSparkle appcast...${NC}"
     bash "$SCRIPT_DIR/data/win32/generate-appcast.sh" "$SETUP_EXE"
     APPCAST_PUSH_DIR="$SCRIPT_DIR/../speccytools.github.io/updates"
@@ -143,6 +214,6 @@ if [[ -n "$SETUP_EXE" ]]; then
         cp -f "$APPCAST_SRC" "$APPCAST_DEST/appcast.xml"
         echo -e "${GREEN}Copied appcast to ${APPCAST_DEST}/appcast.xml${NC}"
     fi
-else
+elif [[ -z "$SETUP_EXE" ]]; then
     echo -e "\n${YELLOW}Skipping appcast generation (no setup.exe).${NC}"
 fi
diff --git a/data/win32/distribution.mk b/data/win32/distribution.mk
index c24df1fb..3a8a8a7e 100644
--- a/data/win32/distribution.mk
+++ b/data/win32/distribution.mk
@@ -110,6 +110,9 @@ dist-win32-dir: 3rdparty-dist
 	elif test -z "$$MINGW_BIN" && test -d "/mingw32/bin"; then \
 	  MINGW_BIN="/mingw32/bin"; \
 	fi; \
+	if test "$$MACOS_MINGW_CROSS" = "1" && test -n "$$MINGW_RUNTIME_DIR"; then \
+	  MINGW_BIN="$$MINGW_RUNTIME_DIR"; \
+	fi; \
 	if test -n "$$MINGW_BIN"; then \
 	  echo "Copying MinGW runtime DLLs from $$MINGW_BIN ..."; \
 	  for dll in libwinpthread-1.dll libstdc++-6.dll libgcc_s_seh-1.dll libgcc_s_dw2-1.dll; do \
diff --git a/deploy.sh b/deploy.sh
new file mode 100755
index 00000000..28fdfeeb
--- /dev/null
+++ b/deploy.sh
@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+# Build the complete FuseX macOS and Windows release from a Mac.
+
+set -euo pipefail
+
+readonly SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+if [[ "$(uname -s)" != "Darwin" ]]; then
+  echo "Error: deploy.sh must be run on macOS." >&2
+  exit 1
+fi
+
+echo "==> Starting macOS deployment"
+bash "$SCRIPT_DIR/deploy_mac.sh"
+
+echo "==> Starting Windows deployment"
+bash "$SCRIPT_DIR/deploy_win.sh"
+
+echo "==> Complete FuseX deployment finished"
diff --git a/deploy_mac.sh b/deploy_mac.sh
new file mode 100755
index 00000000..f96ea45b
--- /dev/null
+++ b/deploy_mac.sh
@@ -0,0 +1,230 @@
+#!/usr/bin/env bash
+
+# Build both the Spectranext-ready and stock FuseX macOS distributions.
+# Xcode uses the signing team and identities configured in FuseX.xcodeproj.
+
+set -euo pipefail
+
+readonly SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+readonly PROJECT_DIR="$SCRIPT_DIR/fusepb"
+readonly PROJECT_PATH="$PROJECT_DIR/FuseX.xcodeproj"
+readonly SETTINGS_PATH="$SCRIPT_DIR/settings.dat"
+readonly BUILD_DIR="$SCRIPT_DIR/build"
+readonly DIST_APP_PATH="$SCRIPT_DIR/dist/FuseX.app"
+readonly APPCAST_REPOSITORY="$SCRIPT_DIR/../speccytools.github.io"
+readonly APPCAST_DESTINATION="$APPCAST_REPOSITORY/appcast.xml"
+readonly SPARKLE_APPCAST_TOOL="${SPARKLE_GENERATE_APPCAST:-$(find "$HOME/Library/Developer/Xcode/DerivedData" -path '*/SourcePackages/artifacts/sparkle/Sparkle/bin/generate_appcast' -type f -print -quit 2>/dev/null)}"
+readonly NOTARIZATION_TIMEOUT="${NOTARIZATION_TIMEOUT:-21600}"
+readonly NOTARIZATION_POLL_INTERVAL="${NOTARIZATION_POLL_INTERVAL:-60}"
+
+restore_settings() {
+  git -C "$SCRIPT_DIR" restore --source=HEAD -- settings.dat
+}
+
+handle_interrupt() {
+  exit 130
+}
+
+trap restore_settings EXIT
+trap handle_interrupt INT TERM HUP
+
+if [[ "$(uname -s)" != "Darwin" ]]; then
+  echo "Error: deploy_mac.sh must be run on macOS." >&2
+  exit 1
+fi
+
+if ! command -v git >/dev/null 2>&1; then
+  echo "Error: required command not found: git" >&2
+  exit 1
+fi
+
+# Always begin from the committed settings, including when a later preflight
+# check fails. The EXIT trap also guarantees that the file is restored.
+restore_settings
+
+if [[ ! -d "$APPCAST_REPOSITORY/.git" ]]; then
+  echo "Error: appcast repository not found: $APPCAST_REPOSITORY" >&2
+  exit 1
+fi
+
+if [[ -z "$SPARKLE_APPCAST_TOOL" || ! -x "$SPARKLE_APPCAST_TOOL" ]]; then
+  echo "Error: Sparkle generate_appcast tool not found." >&2
+  echo "Build or resolve the FuseX Sparkle package first, or set SPARKLE_GENERATE_APPCAST." >&2
+  exit 1
+fi
+
+for command_name in make perl plutil xcodebuild create-dmg; do
+  if ! command -v "$command_name" >/dev/null 2>&1; then
+    echo "Error: required command not found: $command_name" >&2
+    exit 1
+  fi
+done
+
+if ! [[ "$NOTARIZATION_TIMEOUT" =~ ^[1-9][0-9]*$ ]]; then
+  echo "Error: NOTARIZATION_TIMEOUT must be a positive number of seconds." >&2
+  exit 1
+fi
+
+if ! [[ "$NOTARIZATION_POLL_INTERVAL" =~ ^[1-9][0-9]*$ ]]; then
+  echo "Error: NOTARIZATION_POLL_INTERVAL must be a positive number of seconds." >&2
+  exit 1
+fi
+
+make_spectranext_settings() {
+  restore_settings
+
+  perl -pi -e \
+    's/^spectranet,[ \t]*boolean,[ \t]*[01][ \t]*$/spectranet, boolean, 1/; s/^start_machine,[ \t]*string,[ \t]*"[^"]*",,[ \t]*'"'"'m'"'"',[ \t]*machine[ \t]*$/start_machine, string, "128",, '"'"'m'"'"', machine/' \
+    "$SETTINGS_PATH"
+
+  if ! grep -Fqx 'spectranet, boolean, 1' "$SETTINGS_PATH" || \
+     ! grep -Fqx 'start_machine, string, "128",, '\''m'\'', machine' "$SETTINGS_PATH"; then
+    echo "Error: failed to apply the Spectranext defaults to settings.dat." >&2
+    exit 1
+  fi
+}
+
+clean_xcode_project() {
+  echo "==> Cleaning FuseX.xcodeproj"
+  (
+    cd "$PROJECT_DIR"
+    xcodebuild clean \
+      -project "$PROJECT_PATH" \
+      -scheme FuseX \
+      -configuration Deployment
+  )
+}
+
+create_archive() {
+  local archive_name="$1"
+  local archive_path="$BUILD_DIR/$archive_name.xcarchive"
+
+  rm -rf "$archive_path"
+  make -C "$SCRIPT_DIR" archive "ARCHIVE_PATH=build/$archive_name.xcarchive"
+
+  if [[ ! -d "$archive_path" ]]; then
+    echo "Error: Xcode did not create $archive_path" >&2
+    exit 1
+  fi
+
+  CREATED_ARCHIVE_PATH="$archive_path"
+}
+
+upload_for_direct_distribution() {
+  local archive_path="$1"
+  local variant_name="$2"
+  local export_options="$BUILD_DIR/ExportOptions-${variant_name}.plist"
+  local upload_path="$BUILD_DIR/${variant_name}-upload"
+
+  rm -rf "$upload_path"
+  rm -f "$export_options"
+  plutil -create xml1 "$export_options"
+  plutil -insert method -string developer-id "$export_options"
+  plutil -insert destination -string upload "$export_options"
+
+  echo "==> Uploading $variant_name archive for Direct Distribution"
+  xcodebuild -exportArchive \
+    -archivePath "$archive_path" \
+    -exportPath "$upload_path" \
+    -exportOptionsPlist "$export_options" \
+    -allowProvisioningUpdates
+}
+
+wait_and_export_notarized_app() {
+  local archive_path="$1"
+  local variant_name="$2"
+  local started_at="$SECONDS"
+  local attempt_log="$BUILD_DIR/export-notarized-${variant_name}.log"
+
+  echo "==> Waiting for Apple to notarize $variant_name"
+  while (( SECONDS - started_at < NOTARIZATION_TIMEOUT )); do
+    rm -rf "$DIST_APP_PATH"
+    mkdir -p "$SCRIPT_DIR/dist"
+
+    if xcodebuild -exportNotarizedApp \
+      -archivePath "$archive_path" \
+      -exportPath "$SCRIPT_DIR/dist" >"$attempt_log" 2>&1; then
+      if [[ ! -d "$DIST_APP_PATH" ]]; then
+        echo "Error: notarized export completed without creating $DIST_APP_PATH" >&2
+        exit 1
+      fi
+      echo "==> Exported notarized app to $DIST_APP_PATH"
+      return
+    fi
+
+    echo "    Notarization is not ready; checking again in ${NOTARIZATION_POLL_INTERVAL}s"
+    sleep "$NOTARIZATION_POLL_INTERVAL"
+  done
+
+  echo "Error: notarization of $variant_name did not finish within ${NOTARIZATION_TIMEOUT}s." >&2
+  echo "Last Xcode response:" >&2
+  tail -n 30 "$attempt_log" >&2
+  exit 1
+}
+
+make_dmg() {
+  local output_name="$1"
+  local standard_name="FuseX-${FUSEX_VERSION}.dmg"
+
+  make -C "$SCRIPT_DIR" dmg
+  if [[ ! -f "$SCRIPT_DIR/$standard_name" ]]; then
+    echo "Error: make dmg did not create $standard_name" >&2
+    exit 1
+  fi
+
+  if [[ "$output_name" != "$standard_name" ]]; then
+    mv -f "$SCRIPT_DIR/$standard_name" "$SCRIPT_DIR/$output_name"
+  fi
+  echo "==> Created $SCRIPT_DIR/$output_name"
+}
+
+generate_appcast() {
+  local dmg_name="FuseX-${FUSEX_VERSION}.dmg"
+
+  echo "==> Generating macOS Sparkle appcast"
+  make -C "$SCRIPT_DIR" appcast \
+    "APPCAST_ARCHIVE=./$dmg_name" \
+    "SPARKLE_GENERATE_APPCAST=$SPARKLE_APPCAST_TOOL"
+
+  if [[ ! -f "$BUILD_DIR/appcast/appcast.xml" ]]; then
+    echo "Error: appcast generation did not create $BUILD_DIR/appcast/appcast.xml" >&2
+    exit 1
+  fi
+
+  cp -f "$BUILD_DIR/appcast/appcast.xml" "$APPCAST_DESTINATION"
+  echo "==> Updated $APPCAST_DESTINATION"
+}
+
+FUSEX_VERSION="$(awk -F'= ' '/MARKETING_VERSION = / { gsub(/[";]/, "", $2); print $2; exit }' "$PROJECT_PATH/project.pbxproj")"
+if [[ -z "$FUSEX_VERSION" ]]; then
+  echo "Error: could not determine MARKETING_VERSION from FuseX.xcodeproj." >&2
+  exit 1
+fi
+readonly FUSEX_VERSION
+
+mkdir -p "$BUILD_DIR"
+
+echo "==> Building FuseX $FUSEX_VERSION distributions"
+make_spectranext_settings
+clean_xcode_project
+
+create_archive FuseX-spectranext
+spectranext_archive="$CREATED_ARCHIVE_PATH"
+upload_for_direct_distribution "$spectranext_archive" spectranext
+wait_and_export_notarized_app "$spectranext_archive" spectranext
+make_dmg "FuseX-spectranext-${FUSEX_VERSION}.dmg"
+
+echo "==> Restoring stock FuseX settings"
+restore_settings
+
+create_archive FuseX
+stock_archive="$CREATED_ARCHIVE_PATH"
+upload_for_direct_distribution "$stock_archive" stock
+wait_and_export_notarized_app "$stock_archive" stock
+make_dmg "FuseX-${FUSEX_VERSION}.dmg"
+generate_appcast
+
+echo "==> Deployment complete"
+echo "    $SCRIPT_DIR/FuseX-spectranext-${FUSEX_VERSION}.dmg"
+echo "    $SCRIPT_DIR/FuseX-${FUSEX_VERSION}.dmg"
+echo "    $APPCAST_DESTINATION"
diff --git a/deploy_win.sh b/deploy_win.sh
new file mode 100755
index 00000000..c6b35d92
--- /dev/null
+++ b/deploy_win.sh
@@ -0,0 +1,120 @@
+#!/usr/bin/env bash
+
+# Build both the Spectranext-ready and stock FuseX Windows installers on macOS.
+
+set -euo pipefail
+
+readonly SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+readonly SETTINGS_PATH="$SCRIPT_DIR/settings.dat"
+readonly APPCAST_REPOSITORY="$SCRIPT_DIR/../speccytools.github.io"
+readonly APPCAST_DESTINATION="$APPCAST_REPOSITORY/updates/windows/appcast.xml"
+readonly MAKEFILE_BACKUP="$(mktemp "${TMPDIR:-/tmp}/fusex-deploy-win-makefile.XXXXXX")"
+readonly TEST_DRIVER_PATH="$SCRIPT_DIR/test-driver"
+TEST_DRIVER_EXISTED=0
+if [[ -e "$TEST_DRIVER_PATH" ]]; then
+  TEST_DRIVER_EXISTED=1
+fi
+
+cp -p "$SCRIPT_DIR/Makefile" "$MAKEFILE_BACKUP"
+
+restore_settings() {
+  git -C "$SCRIPT_DIR" restore --source=HEAD -- settings.dat
+}
+
+handle_interrupt() {
+  exit 130
+}
+
+cleanup() {
+  restore_settings || true
+  cp -p "$MAKEFILE_BACKUP" "$SCRIPT_DIR/Makefile"
+  rm -f "$MAKEFILE_BACKUP"
+  if [[ "$TEST_DRIVER_EXISTED" == "0" ]]; then
+    rm -f "$TEST_DRIVER_PATH"
+  fi
+}
+
+trap cleanup EXIT
+trap handle_interrupt INT TERM HUP
+
+if [[ "$(uname -s)" != "Darwin" ]]; then
+  echo "Error: deploy_win.sh must be run on macOS." >&2
+  exit 1
+fi
+
+if [[ ! -d "$APPCAST_REPOSITORY/.git" ]]; then
+  echo "Error: appcast repository not found: $APPCAST_REPOSITORY" >&2
+  exit 1
+fi
+
+for command_name in git perl make pkg-config cmake makensis autoreconf automake glibtoolize \
+  x86_64-w64-mingw32-gcc x86_64-w64-mingw32-g++ \
+  x86_64-w64-mingw32-ar x86_64-w64-mingw32-ranlib \
+  x86_64-w64-mingw32-strip x86_64-w64-mingw32-windres; do
+  if ! command -v "$command_name" >/dev/null 2>&1; then
+    echo "Error: required command not found: $command_name" >&2
+    echo "Install the macOS build tools with: brew install mingw-w64 nsis autoconf automake libtool" >&2
+    exit 1
+  fi
+done
+
+# Begin from the committed defaults and restore them even if either build fails.
+restore_settings
+
+make_spectranext_settings() {
+  restore_settings
+
+  perl -pi -e \
+    's/^spectranet,[ \t]*boolean,[ \t]*[01][ \t]*$/spectranet, boolean, 1/; s/^start_machine,[ \t]*string,[ \t]*"[^"]*",,[ \t]*'"'"'m'"'"',[ \t]*machine[ \t]*$/start_machine, string, "128",, '"'"'m'"'"', machine/' \
+    "$SETTINGS_PATH"
+
+  if ! grep -Fqx 'spectranet, boolean, 1' "$SETTINGS_PATH" || \
+     ! grep -Fqx 'start_machine, string, "128",, '\''m'\'', machine' "$SETTINGS_PATH"; then
+    echo "Error: failed to apply the Spectranext defaults to settings.dat." >&2
+    exit 1
+  fi
+}
+
+build_installer() {
+  local variant_name="$1"
+  local skip_appcast="$2"
+
+  echo "==> Building the $variant_name Windows installer"
+  WIN32_CLEAN=1 \
+  WIN32_DIST_TARGET=dist-win32-exe \
+  REQUIRE_NSIS=1 \
+  SKIP_APPCAST="$skip_appcast" \
+    bash "$SCRIPT_DIR/build_win32.sh"
+
+  PACKAGE_VERSION="$(sed -n 's/^#define PACKAGE_VERSION "\(.*\)"/\1/p' "$SCRIPT_DIR/config.h" | head -1)"
+  if [[ -z "$PACKAGE_VERSION" ]]; then
+    echo "Error: could not determine PACKAGE_VERSION from config.h." >&2
+    exit 1
+  fi
+
+  BUILT_INSTALLER="$SCRIPT_DIR/fusex-${PACKAGE_VERSION}-win32-setup.exe"
+  if [[ ! -f "$BUILT_INSTALLER" ]]; then
+    echo "Error: NSIS did not create $BUILT_INSTALLER" >&2
+    exit 1
+  fi
+}
+
+make_spectranext_settings
+build_installer Spectranext 1
+spectranext_installer="$SCRIPT_DIR/fusex-spectranext-${PACKAGE_VERSION}-win32-setup.exe"
+mv -f "$BUILT_INSTALLER" "$spectranext_installer"
+
+echo "==> Restoring stock FuseX settings"
+restore_settings
+build_installer stock 0
+stock_installer="$BUILT_INSTALLER"
+
+if [[ ! -f "$APPCAST_DESTINATION" ]]; then
+  echo "Error: Windows appcast was not created at $APPCAST_DESTINATION" >&2
+  exit 1
+fi
+
+echo "==> Deployment complete"
+echo "    $spectranext_installer"
+echo "    $stock_installer"
+echo "    $APPCAST_DESTINATION"