diff --git a/cmake/caches/Runtime-Android-i686.cmake b/cmake/caches/Runtime-Android-i686.cmake
new file mode 100644
index 0000000000000..66d3063709924
--- /dev/null
+++ b/cmake/caches/Runtime-Android-i686.cmake
@@ -0,0 +1,24 @@
+
+set(SWIFT_HOST_VARIANT_SDK ANDROID CACHE STRING "")
+set(SWIFT_HOST_VARIANT_ARCH i686 CACHE STRING "")
+
+# NOTE(compnerd) disable the tools, we are trying to build just the standard
+# library.
+set(SWIFT_INCLUDE_TOOLS NO CACHE BOOL "")
+
+# NOTE(compnerd) cannot build tests since the tests require the toolchain
+set(SWIFT_INCLUDE_TESTS NO CACHE BOOL "")
+
+# NOTE(compnerd) cannot build docs since that requires perl
+set(SWIFT_INCLUDE_DOCS NO CACHE BOOL "")
+
+# NOTE(compnerd) these are part of the toolchain, not the runtime.
+set(SWIFT_BUILD_SOURCEKIT NO CACHE BOOL "")
+
+# NOTE(compnerd) build with the compiler specified, not a just built compiler.
+set(SWIFT_BUILD_RUNTIME_WITH_HOST_COMPILER YES CACHE BOOL "")
+
+set(SWIFT_SDK_ANDROID_ARCHITECTURES i686 CACHE STRING "")
+
+# NOTE(compnerd) this is lollipop, which seems to still have decent usage.
+set(SWIFT_ANDROID_API_LEVEL 21 CACHE STRING "")
diff --git a/cmake/caches/Runtime-Android-x86_64.cmake b/cmake/caches/Runtime-Android-x86_64.cmake
new file mode 100644
index 0000000000000..8780313aaa3ca
--- /dev/null
+++ b/cmake/caches/Runtime-Android-x86_64.cmake
@@ -0,0 +1,24 @@
+
+set(SWIFT_HOST_VARIANT_SDK ANDROID CACHE STRING "")
+set(SWIFT_HOST_VARIANT_ARCH x86_64 CACHE STRING "")
+
+# NOTE(compnerd) disable the tools, we are trying to build just the standard
+# library.
+set(SWIFT_INCLUDE_TOOLS NO CACHE BOOL "")
+
+# NOTE(compnerd) cannot build tests since the tests require the toolchain
+set(SWIFT_INCLUDE_TESTS NO CACHE BOOL "")
+
+# NOTE(compnerd) cannot build docs since that requires perl
+set(SWIFT_INCLUDE_DOCS NO CACHE BOOL "")
+
+# NOTE(compnerd) these are part of the toolchain, not the runtime.
+set(SWIFT_BUILD_SOURCEKIT NO CACHE BOOL "")
+
+# NOTE(compnerd) build with the compiler specified, not a just built compiler.
+set(SWIFT_BUILD_RUNTIME_WITH_HOST_COMPILER YES CACHE BOOL "")
+
+set(SWIFT_SDK_ANDROID_ARCHITECTURES x86_64 CACHE STRING "")
+
+# NOTE(compnerd) this is lollipop, which seems to still have decent usage.
+set(SWIFT_ANDROID_API_LEVEL 21 CACHE STRING "")
diff --git a/stdlib/cmake/modules/AddSwiftStdlib.cmake b/stdlib/cmake/modules/AddSwiftStdlib.cmake
index d95ce397e7726..aa17bf5e42783 100644
--- a/stdlib/cmake/modules/AddSwiftStdlib.cmake
+++ b/stdlib/cmake/modules/AddSwiftStdlib.cmake
@@ -541,13 +541,16 @@ function(_add_target_variant_link_flags)
     list(APPEND link_libraries "dl" "log")
     # We need to add the math library, which is linked implicitly by libc++
     list(APPEND result "-lm")
-    if(NOT "${SWIFT_ANDROID_NDK_PATH}" STREQUAL "")
-      if("${SWIFT_ANDROID_NDK_PATH}" MATCHES "r26")
-        file(GLOB RESOURCE_DIR ${SWIFT_SDK_ANDROID_ARCH_${LFLAGS_ARCH}_PATH}/../lib/clang/*)
-      else()
-        file(GLOB RESOURCE_DIR ${SWIFT_SDK_ANDROID_ARCH_${LFLAGS_ARCH}_PATH}/../lib64/clang/*)
+    if(NOT CMAKE_HOST_SYSTEM MATCHES Windows)
+      # The Android resource dir is specified from build.ps1 on windows.
+      if(NOT "${SWIFT_ANDROID_NDK_PATH}" STREQUAL "")
+        if("${SWIFT_ANDROID_NDK_PATH}" MATCHES "r26")
+          file(GLOB RESOURCE_DIR ${SWIFT_SDK_ANDROID_ARCH_${LFLAGS_ARCH}_PATH}/../lib/clang/*)
+        else()
+          file(GLOB RESOURCE_DIR ${SWIFT_SDK_ANDROID_ARCH_${LFLAGS_ARCH}_PATH}/../lib64/clang/*)
+        endif()
+        list(APPEND result "-resource-dir=${RESOURCE_DIR}")
       endif()
-      list(APPEND result "-resource-dir=${RESOURCE_DIR}")
     endif()
 
     # link against the custom C++ library
@@ -3062,9 +3065,14 @@ function(add_swift_target_executable name)
       # it tries to build swift-backtrace it fails because *the compiler*
       # refers to a libswiftCore.so that can't be found.
 
+      if(SWIFTEXE_TARGET_NOSWIFTRT)
+        set(NOSWIFTRT_KEYWORD "NOSWIFTRT")
+      else()
+        set(NOSWIFTRT_KEYWORD "")
+      endif()
       _add_swift_target_executable_single(
           ${VARIANT_NAME}
-          ${SWIFTEXE_TARGET_NOSWIFTRT_keyword}
+          ${NOSWIFTRT_KEYWORD}
           ${SWIFTEXE_TARGET_SOURCES}
           DEPENDS
             ${SWIFTEXE_TARGET_DEPENDS_with_suffix}
diff --git a/stdlib/public/ClangOverlays/CMakeLists.txt b/stdlib/public/ClangOverlays/CMakeLists.txt
index cb9316b6ace64..f53382567e45e 100644
--- a/stdlib/public/ClangOverlays/CMakeLists.txt
+++ b/stdlib/public/ClangOverlays/CMakeLists.txt
@@ -1,17 +1,19 @@
-add_swift_target_library(swift_Builtin_float
-    ${SWIFT_STDLIB_LIBRARY_BUILD_TYPES}
-    IS_SDK_OVERLAY
+if(NOT DEFINED SWIFT_BUILD_CLANG_OVERLAYS_SKIP_BUILTIN_FLOAT OR NOT SWIFT_BUILD_CLANG_OVERLAYS_SKIP_BUILTIN_FLOAT)
+  add_swift_target_library(swift_Builtin_float
+      ${SWIFT_STDLIB_LIBRARY_BUILD_TYPES}
+      IS_SDK_OVERLAY
 
-    GYB_SOURCES
-      float.swift.gyb
+      GYB_SOURCES
+        float.swift.gyb
 
-    SWIFT_COMPILE_FLAGS
-      ${SWIFT_RUNTIME_SWIFT_COMPILE_FLAGS}
-      ${SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS}
-      -Xfrontend -previous-module-installname-map-file -Xfrontend "${SWIFT_SOURCE_DIR}/stdlib/linker-support/previous-module-installname.json"
+      SWIFT_COMPILE_FLAGS
+        ${SWIFT_RUNTIME_SWIFT_COMPILE_FLAGS}
+        ${SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS}
+        -Xfrontend -previous-module-installname-map-file -Xfrontend "${SWIFT_SOURCE_DIR}/stdlib/linker-support/previous-module-installname.json"
 
-    LINK_FLAGS
-      ${SWIFT_RUNTIME_SWIFT_LINK_FLAGS}
+      LINK_FLAGS
+        ${SWIFT_RUNTIME_SWIFT_LINK_FLAGS}
 
-    INSTALL_IN_COMPONENT stdlib
-    MACCATALYST_BUILD_FLAVOR zippered)
+      INSTALL_IN_COMPONENT stdlib
+      MACCATALYST_BUILD_FLAVOR zippered)
+endif()
diff --git a/stdlib/public/Concurrency/DispatchGlobalExecutor.inc b/stdlib/public/Concurrency/DispatchGlobalExecutor.inc
index 8010d123dd57e..a2d0bb8a12abe 100644
--- a/stdlib/public/Concurrency/DispatchGlobalExecutor.inc
+++ b/stdlib/public/Concurrency/DispatchGlobalExecutor.inc
@@ -42,6 +42,9 @@ struct MinimalDispatchObjectHeader {
   int Opaque1;
   void *Linkage;
 };
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wgnu-offsetof-extensions"
 static_assert(
     offsetof(Job, metadata) == offsetof(MinimalDispatchObjectHeader, VTable),
     "Job Metadata field must match location of Dispatch VTable field.");
@@ -49,6 +52,7 @@ static_assert(offsetof(Job, SchedulerPrivate[Job::DispatchLinkageIndex]) ==
                   offsetof(MinimalDispatchObjectHeader, Linkage),
               "Dispatch Linkage field must match Job "
               "SchedulerPrivate[DispatchLinkageIndex].");
+#pragma clang diagnostic pop
 
 /// The function passed to dispatch_async_f to execute a job.
 static void __swift_run_job(void *_job) {
diff --git a/stdlib/public/core/CMakeLists.txt b/stdlib/public/core/CMakeLists.txt
index 4d7646ffd428f..1f62b9ad93321 100644
--- a/stdlib/public/core/CMakeLists.txt
+++ b/stdlib/public/core/CMakeLists.txt
@@ -262,8 +262,8 @@ if(SWIFT_STDLIB_ENABLE_VECTOR_TYPES)
   list(APPEND SWIFTLIB_EMBEDDED_GYB_SOURCES SIMDConcreteOperations.swift.gyb SIMDVectorTypes.swift.gyb)
 endif()
 
-# Freestanding and Linux builds both have failures to resolve.
-if(NOT BOOTSTRAPPING_MODE STREQUAL "OFF" AND NOT SWIFT_FREESTANDING_FLAVOR AND NOT SWIFT_HOST_VARIANT_SDK STREQUAL "LINUX")
+# Freestanding and Linux/Android builds both have failures to resolve.
+if(NOT BOOTSTRAPPING_MODE STREQUAL "OFF" AND NOT SWIFT_FREESTANDING_FLAVOR AND NOT SWIFT_HOST_VARIANT_SDK STREQUAL "LINUX" AND NOT SWIFT_HOST_VARIANT_SDK STREQUAL "ANDROID")
   list(APPEND SWIFTLIB_SOURCES ObjectIdentifier+DebugDescription.swift)
 endif()
 
diff --git a/stdlib/tools/swift-reflection-test/CMakeLists.txt b/stdlib/tools/swift-reflection-test/CMakeLists.txt
index d66bf30273746..2dd113998e4fd 100644
--- a/stdlib/tools/swift-reflection-test/CMakeLists.txt
+++ b/stdlib/tools/swift-reflection-test/CMakeLists.txt
@@ -1,4 +1,5 @@
 add_swift_target_executable(swift-reflection-test BUILD_WITH_STDLIB
+  NOSWIFTRT
   swift-reflection-test.c
   overrides.c
   LINK_LIBRARIES
diff --git a/utils/build.ps1 b/utils/build.ps1
index bfac3272df009..a264020e4f525 100644
--- a/utils/build.ps1
+++ b/utils/build.ps1
@@ -32,6 +32,15 @@ The debug information format for C/C++ code: dwarf or codeview.
 .PARAMETER SwiftDebugFormat
 The debug information format for Swift code: dwarf or codeview.
 
+.PARAMETER AndroidAPILevel
+The API Level to target when building the Android SDKs
+
+.PARAMETER Android
+When set, build android SDKs.
+
+.PARAMETER AndroidSDKs
+An array of architectures for which the Android Swift SDK should be built.
+
 .PARAMETER WindowsSDKs
 An array of architectures for which the Windows Swift SDK should be built.
 
@@ -45,6 +54,9 @@ The toolchain snapshot to build the early components with.
 .PARAMETER PinnedSHA256
 The SHA256 for the pinned toolchain.
 
+.PARAMETER AndroidNDKVersion
+The version number of the Android NDK to be used.
+
 .PARAMETER WinSDKVersion
 The version number of the Windows SDK to be used.
 Overrides the value resolved by the Visual Studio command prompt.
@@ -96,12 +108,16 @@ param(
   [string] $ImageRoot = "S:",
   [string] $CDebugFormat = "dwarf",
   [string] $SwiftDebugFormat = "dwarf",
+  [string] $AndroidAPILevel = 28,
+  [string[]] $AndroidSDKs = @(),
   [string[]] $WindowsSDKs = @("X64","X86","Arm64"),
   [string] $ProductVersion = "0.0.0",
   [string] $PinnedBuild = "",
   [string] $PinnedSHA256 = "",
   [string] $PythonVersion = "3.9.10",
+  [string] $AndroidNDKVersion = "r26b",
   [string] $WinSDKVersion = "",
+  [switch] $Android = $false,
   [switch] $SkipBuild = $false,
   [switch] $SkipRedistInstall = $false,
   [switch] $SkipPackaging = $false,
@@ -165,10 +181,20 @@ if (-not (Test-Path $python)) {
   }
 }
 
+if ($Android -and ($AndroidSDKs.Length -eq 0)) {
+  # Enable all android SDKs by default.
+  $AndroidSDKs = @("aarch64","armv7","i686","x86_64")
+}
 # Work around limitations of cmd passing in array arguments via powershell.exe -File
+if ($AndroidSDKs.Length -eq 1) { $AndroidSDKs = $AndroidSDKs[0].Split(",") }
 if ($WindowsSDKs.Length -eq 1) { $WindowsSDKs = $WindowsSDKs[0].Split(",") }
 if ($Test.Length -eq 1) { $Test = $Test[0].Split(",") }
 
+if ($AndroidSDKs.Length -gt 0) {
+  # Always enable android when one of the SDKs is specified.
+  $Android = $true
+}
+
 if ($Test -contains "*") {
   # Explicitly don't include llbuild yet since tests are known to fail on Windows
   $Test = @("swift", "dispatch", "foundation", "xctest")
@@ -219,6 +245,58 @@ $ArchARM64 = @{
   ToolchainInstallRoot = "$BinaryCache\arm64\toolchains\$ProductVersion+Asserts";
 }
 
+$AndroidARM64 = @{
+  AndroidArchABI = "arm64-v8a";
+  BinaryDir = "bin64a";
+  CMakeName = "aarch64";
+  LLVMName = "aarch64";
+  LLVMTarget = "aarch64-unknown-linux-android$AndroidAPILevel";
+  BuildID = 400;
+  BinaryCache = "$BinaryCache\aarch64";
+  PlatformInstallRoot = "$BinaryCache\arm64\Android.platform";
+  SDKInstallRoot = "$BinaryCache\arm64\Android.platform\Developer\SDKs\Android.sdk";
+  XCTestInstallRoot = "$BinaryCache\arm64\Android.platform\Developer\Library\XCTest-development";
+}
+
+$AndroidARMv7 = @{
+  AndroidArchABI = "armeabi-v7a";
+  BinaryDir = "bina";
+  CMakeName = "armv7-a";
+  LLVMName = "armv7";
+  LLVMTarget = "armv7-unknown-linux-androideabi$AndroidAPILevel";
+  BuildID = 500;
+  BinaryCache = "$BinaryCache\armv7";
+  PlatformInstallRoot = "$BinaryCache\armv7\Android.platform";
+  SDKInstallRoot = "$BinaryCache\armv7\Android.platform\Developer\SDKs\Android.sdk";
+  XCTestInstallRoot = "$BinaryCache\armv7\Android.platform\Developer\Library\XCTest-development";
+}
+
+$AndroidX86 = @{
+  AndroidArchABI = "x86";
+  BinaryDir = "bin";
+  CMakeName = "i686";
+  LLVMName = "i686";
+  LLVMTarget = "i686-unknown-linux-android$AndroidAPILevel";
+  BuildID = 600;
+  BinaryCache = "$BinaryCache\i686";
+  PlatformInstallRoot = "$BinaryCache\x86\Android.platform";
+  SDKInstallRoot = "$BinaryCache\x86\Android.platform\Developer\SDKs\Android.sdk";
+  XCTestInstallRoot = "$BinaryCache\x86\Android.platform\Developer\Library\XCTest-development";
+}
+
+$AndroidX64 = @{
+  AndroidArchABI = "x86_64";
+  BinaryDir = "bin64";
+  CMakeName = "x86_64";
+  LLVMName = "x86_64";
+  LLVMTarget = "x86_64-unknown-linux-android$AndroidAPILevel";
+  BuildID = 700;
+  BinaryCache = "$BinaryCache\x86_64";
+  PlatformInstallRoot = "$BinaryCache\x64\Android.platform";
+  SDKInstallRoot = "$BinaryCache\x64\Android.platform\Developer\SDKs\Android.sdk";
+  XCTestInstallRoot = "$BinaryCache\x64\Android.platform\Developer\Library\XCTest-development";
+}
+
 $HostArch = switch ($HostArchName) {
   "AMD64" { $ArchX64 }
   "ARM64" { $ArchARM64 }
@@ -235,6 +313,11 @@ $IsCrossCompiling = $HostArchName -ne $BuildArchName
 
 $TimingData = New-Object System.Collections.Generic.List[System.Object]
 
+function Get-AndroidNDKPath {
+  $androidNDKPath = Join-Path -Path $BinaryCache -ChildPath "android-ndk-$AndroidNDKVersion"
+  return $androidNDKPath
+}
+
 function Get-InstallDir($Arch) {
   if ($Arch -eq $HostArch) {
     $ProgramFilesName = "Program Files"
@@ -251,6 +334,10 @@ function Get-InstallDir($Arch) {
   return "$ImageRoot\$ProgramFilesName\Swift"
 }
 
+function Get-HostSwiftSDK() {
+  return ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk"))
+}
+
 $NugetRoot = "$BinaryCache\nuget"
 $PinnedToolchain = [IO.Path]::GetFileNameWithoutExtension($PinnedBuild)
 
@@ -261,6 +348,20 @@ $LibraryRoot = "$ImageRoot\Library"
 $HostArch.ToolchainInstallRoot = "$(Get-InstallDir $HostArch)\Toolchains\$ProductVersion+Asserts"
 
 # Resolve the architectures received as argument
+$AndroidSDKArchs = @($AndroidSDKs | ForEach-Object {
+  switch ($_) {
+    "aarch64" { $AndroidARM64 }
+    "armv7" { $AndroidARMv7 }
+    "i686" { $AndroidX86 }
+    "x86_64" { $AndroidX64 }
+    default { throw "Unknown architecture $_" }
+  }
+})
+if ($Android) {
+  if ($HostArch -ne $ArchX64) {
+    throw "Unsupported host architecture for building android SDKs"
+  }
+}
 $WindowsSDKArchs = @($WindowsSDKs | ForEach-Object {
   switch ($_) {
     "X64" { $ArchX64 }
@@ -506,6 +607,32 @@ function Fetch-Dependencies {
     }
   }
 
+  function Extract-ZipFile {
+    param (
+        [string]$ZipFileName,
+        [string]$BinaryCache,
+        [string]$ExtractPath
+    )
+
+    $source = Join-Path -Path $BinaryCache -ChildPath $ZipFileName
+    $destination = Join-Path -Path $BinaryCache -ChildPath $ExtractPath
+
+    # Check if the extracted directory already exists and is up to date.
+    if (Test-Path $destination) {
+        $zipLastWriteTime = (Get-Item $source).LastWriteTime
+        $extractedLastWriteTime = (Get-Item $destination).LastWriteTime
+        # Compare the last write times
+        if ($zipLastWriteTime -le $extractedLastWriteTime) {
+            Write-Output "'$ZipFileName' is already extracted and up to date."
+            return
+        }
+    }
+
+    Write-Output "Extracting '$ZipFileName' ..."
+    New-Item -ItemType Directory -ErrorAction Ignore -Path $BinaryCache | Out-Null
+    Expand-Archive -Path $source -DestinationPath $BinaryCache -Force
+  }
+
   $WiXVersion = "4.0.4"
   $WiXURL = "https://www.nuget.org/api/v2/package/wix/$WiXVersion"
   $WiXHash = "A9CA12214E61BB49430A8C6E5E48AC5AE6F27DC82573B5306955C4D35F2D34E2"
@@ -552,6 +679,18 @@ function Fetch-Dependencies {
     Download-Python $BuildArchName
   }
 
+  if ($Android) {
+    # Only a specific NDK version is supported right now.
+    if ($AndroidNDKVersion -ne "r26b") {
+      throw "Unsupported Android NDK version"
+    }
+    $NDKURL = "https://dl.google.com/android/repository/android-ndk-r26b-windows.zip"
+    $NDKHash = "A478D43D4A45D0D345CDA6BE50D79642B92FB175868D9DC0DFC86181D80F691E"
+    DownloadAndVerify $NDKURL "$BinaryCache\android-ndk-$AndroidNDKVersion-windows.zip" $NDKHash
+
+    Extract-ZipFile -ZipFileName "android-ndk-$AndroidNDKVersion-windows.zip" -BinaryCache $BinaryCache -ExtractPath "android-ndk-$AndroidNDKVersion"
+  }
+
   if ($WinSDKVersion) {
     try {
       # Check whether VsDevShell can already resolve the requested Windows SDK Version
@@ -696,12 +835,40 @@ function Build-CMakeProject {
       TryAdd-KeyValue $Defines CMAKE_SYSTEM_PROCESSOR $Arch.CMakeName
     }
 
+    if ($Platform -eq "Android") {
+      $vsWherePath = "${env:ProgramFiles(x86)}\Microsoft Visual Studio\Installer\vswhere.exe"
+      $vsInstallPath = & $vsWherePath -latest -property installationPath
+      if (Test-Path "${vsInstallPath}\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin") {
+        $env:Path = "${vsInstallPath}\Common7\IDE\CommonExtensions\Microsoft\CMake\CMake\bin;${vsInstallPath}\Common7\IDE\CommonExtensions\Microsoft\CMake\Ninja;${env:Path}"
+        TryAdd-KeyValue $Defines CMAKE_MAKE_PROGRAM "${vsInstallPath}\Common7\IDE\CommonExtensions\Microsoft\CMake\Ninja\ninja.exe"
+      } else {
+        throw "Missing CMake and Ninja in the visual studio installation that are needed to build Android"
+      }
+      $androidNDKPath = Get-AndroidNDKPath
+      TryAdd-KeyValue $Defines CMAKE_C_COMPILER (Join-Path -Path $androidNDKPath -ChildPath "toolchains\llvm\prebuilt\windows-x86_64\bin\clang.exe")
+      TryAdd-KeyValue $Defines CMAKE_CXX_COMPILER (Join-Path -Path $androidNDKPath -ChildPath "toolchains\llvm\prebuilt\windows-x86_64\bin\clang++.exe")
+      TryAdd-KeyValue $Defines CMAKE_ANDROID_API "$AndroidAPILevel"
+      TryAdd-KeyValue $Defines CMAKE_ANDROID_ARCH_ABI $Arch.AndroidArchABI
+      TryAdd-KeyValue $Defines CMAKE_ANDROID_NDK "$androidNDKPath"
+      TryAdd-KeyValue $Defines SWIFT_ANDROID_NDK_PATH "$androidNDKPath"
+      TryAdd-KeyValue $Defines CMAKE_C_COMPILER_WORKS YES
+      TryAdd-KeyValue $Defines CMAKE_CXX_COMPILER_WORKS YES
+      # The current Android NDK ships with Clang 17,
+      # which doesn't provide the _Builtin_float module.
+      TryAdd-KeyValue $Defines SWIFT_BUILD_CLANG_OVERLAYS_SKIP_BUILTIN_FLOAT YES
+    }
+
     TryAdd-KeyValue $Defines CMAKE_BUILD_TYPE Release
     TryAdd-KeyValue $Defines CMAKE_MT "mt"
 
     $CFlags = @()
-    if ($Platform -eq "Windows") {
-      $CFlags = @("/GS-", "/Gw", "/Gy", "/Oi", "/Oy", "/Zc:inline")
+    switch ($Platform) {
+      Windows {
+        $CFlags = @("/GS-", "/Gw", "/Gy", "/Oi", "/Oy", "/Zc:inline")
+      }
+      Android {
+        $CFlags = @("--sysroot=$(Get-AndroidNDKPath)\toolchains\llvm\prebuilt\windows-x86_64\sysroot")
+      }
     }
 
     $CXXFlags = @()
@@ -712,7 +879,7 @@ function Build-CMakeProject {
     if ($UseMSVCCompilers.Contains("C") -Or $UseMSVCCompilers.Contains("CXX") -Or
         $UseBuiltCompilers.Contains("C") -Or $UseBuiltCompilers.Contains("CXX") -Or
         $UsePinnedCompilers.Contains("C") -Or $UsePinnedCompilers.Contains("CXX")) {
-      if ($DebugInfo) {
+      if ($DebugInfo -and $Platform -eq "Windows") {
         Append-FlagsDefine $Defines CMAKE_MSVC_DEBUG_INFORMATION_FORMAT Embedded
         Append-FlagsDefine $Defines CMAKE_POLICY_CMP0141 NEW
         # Add additional linker flags for generating the debug info.
@@ -736,23 +903,27 @@ function Build-CMakeProject {
       Append-FlagsDefine $Defines CMAKE_CXX_FLAGS $CXXFlags
     }
     if ($UsePinnedCompilers.Contains("ASM") -Or $UseBuiltCompilers.Contains("ASM")) {
+      $Driver = if ($Platform -eq "Windows") { "clang-cl.exe" } else { "clang.exe" }
       if ($UseBuiltCompilers.Contains("ASM")) {
-        TryAdd-KeyValue $Defines CMAKE_ASM_COMPILER ([IO.Path]::Combine($CompilersBinaryCache, "bin", "clang-cl.exe"))
+        TryAdd-KeyValue $Defines CMAKE_ASM_COMPILER ([IO.Path]::Combine($CompilersBinaryCache, "bin", $Driver))
       } else {
-        TryAdd-KeyValue $Defines CMAKE_ASM_COMPILER (Join-Path -Path (Get-PinnedToolchainTool) -ChildPath "clang-cl.exe")
+        TryAdd-KeyValue $Defines CMAKE_ASM_COMPILER (Join-Path -Path (Get-PinnedToolchainTool) -ChildPath $Driver)
       }
       Append-FlagsDefine $Defines CMAKE_ASM_FLAGS "--target=$($Arch.LLVMTarget)"
-      TryAdd-KeyValue $Defines CMAKE_ASM_COMPILE_OPTIONS_MSVC_RUNTIME_LIBRARY_MultiThreadedDLL "/MD"
+      if ($Platform -eq "Windows") {
+        TryAdd-KeyValue $Defines CMAKE_ASM_COMPILE_OPTIONS_MSVC_RUNTIME_LIBRARY_MultiThreadedDLL "/MD"
+      }
     }
     if ($UsePinnedCompilers.Contains("C") -Or $UseBuiltCompilers.Contains("C")) {
+      $Driver = if ($Platform -eq "Windows") { "clang-cl.exe" } else { "clang.exe" }
       if ($UseBuiltCompilers.Contains("C")) {
-        TryAdd-KeyValue $Defines CMAKE_C_COMPILER ([IO.Path]::Combine($CompilersBinaryCache, "bin", "clang-cl.exe"))
+        TryAdd-KeyValue $Defines CMAKE_C_COMPILER ([IO.Path]::Combine($CompilersBinaryCache, "bin", $Driver))
       } else {
-        TryAdd-KeyValue $Defines CMAKE_C_COMPILER (Join-Path -Path (Get-PinnedToolchainTool) -ChildPath "clang-cl.exe")
+        TryAdd-KeyValue $Defines CMAKE_C_COMPILER (Join-Path -Path (Get-PinnedToolchainTool) -ChildPath $Driver)
       }
       TryAdd-KeyValue $Defines CMAKE_C_COMPILER_TARGET $Arch.LLVMTarget
 
-      if (-not (Test-CMakeAtLeast -Major 3 -Minor 26 -Patch 3)) {
+      if (-not (Test-CMakeAtLeast -Major 3 -Minor 26 -Patch 3) -and $Platform -eq "Windows") {
         # Workaround for https://github.com/ninja-build/ninja/issues/2280
         TryAdd-KeyValue $Defines CMAKE_CL_SHOWINCLUDES_PREFIX "Note: including file: "
       }
@@ -763,14 +934,15 @@ function Build-CMakeProject {
       Append-FlagsDefine $Defines CMAKE_C_FLAGS $CFlags
     }
     if ($UsePinnedCompilers.Contains("CXX") -Or $UseBuiltCompilers.Contains("CXX")) {
+      $Driver = if ($Platform -eq "Windows") { "clang-cl.exe" } else { "clang++.exe" }
       if ($UseBuiltCompilers.Contains("CXX")) {
-        TryAdd-KeyValue $Defines CMAKE_CXX_COMPILER ([IO.Path]::Combine($CompilersBinaryCache, "bin", "clang-cl.exe"))
+        TryAdd-KeyValue $Defines CMAKE_CXX_COMPILER ([IO.Path]::Combine($CompilersBinaryCache, "bin", $Driver))
       } else {
-        TryAdd-KeyValue $Defines CMAKE_CXX_COMPILER (Join-Path -Path (Get-PinnedToolchainTool) -ChildPath "clang-cl.exe")
+        TryAdd-KeyValue $Defines CMAKE_CXX_COMPILER (Join-Path -Path (Get-PinnedToolchainTool) -ChildPath $Driver)
       }
       TryAdd-KeyValue $Defines CMAKE_CXX_COMPILER_TARGET $Arch.LLVMTarget
 
-      if (-not (Test-CMakeAtLeast -Major 3 -Minor 26 -Patch 3)) {
+      if (-not (Test-CMakeAtLeast -Major 3 -Minor 26 -Patch 3) -and $Platform -eq "Windows") {
         # Workaround for https://github.com/ninja-build/ninja/issues/2280
         TryAdd-KeyValue $Defines CMAKE_CL_SHOWINCLUDES_PREFIX "Note: including file: "
       }
@@ -790,7 +962,10 @@ function Build-CMakeProject {
       } else {
         TryAdd-KeyValue $Defines CMAKE_Swift_COMPILER (Join-Path -Path (Get-PinnedToolchainTool) -ChildPath  "swiftc.exe")
       }
-      TryAdd-KeyValue $Defines CMAKE_Swift_COMPILER_TARGET $Arch.LLVMTarget
+      if (-not ($Platform -eq "Windows")) {
+        TryAdd-KeyValue $Defines CMAKE_Swift_COMPILER_WORKS = "YES"
+      }
+      TryAdd-KeyValue $Defines CMAKE_Swift_COMPILER_TARGET $Arch.LLVMTarget.Replace("$AndroidAPILevel", "")
       if ($UseBuiltCompilers.Contains("Swift")) {
         if ($SwiftSDK -ne "") {
           $SwiftArgs += @("-sdk", $SwiftSDK)
@@ -798,9 +973,29 @@ function Build-CMakeProject {
           $RuntimeBinaryCache = Get-TargetProjectBinaryCache $Arch Runtime
           $SwiftResourceDir = "${RuntimeBinaryCache}\lib\swift"
 
+          switch ($Platform) {
+            Windows {
+              $SwiftArgs += @(
+                "-vfsoverlay", "$RuntimeBinaryCache\stdlib\windows-vfs-overlay.yaml",
+                "-strict-implicit-module-context",
+                "-Xcc", "-Xclang", "-Xcc", "-fbuiltin-headers-in-system-modules"
+              )
+            }
+            Android {
+              $androidNDKPath = Get-AndroidNDKPath
+              $SwiftArgs += @("-sdk", "$androidNDKPath\toolchains\llvm\prebuilt\windows-x86_64\sysroot")
+              $SwiftArgs += @(
+                "-Xclang-linker", "-target",
+                "-Xclang-linker", $Arch.LLVMTarget,
+                "-Xclang-linker", "--sysroot",
+                "-Xclang-linker", "$androidNDKPath\toolchains\llvm\prebuilt\windows-x86_64\sysroot",
+                "-Xclang-linker", "-resource-dir",
+                "-Xclang-linker", "$androidNDKPath\toolchains\llvm\prebuilt\windows-x86_64\lib\clang\17"
+              )
+            }
+          }
           $SwiftArgs += @("-resource-dir", "$SwiftResourceDir")
-          $SwiftArgs += @("-L", "$SwiftResourceDir\windows")
-          $SwiftArgs += @("-vfsoverlay", "$RuntimeBinaryCache\stdlib\windows-vfs-overlay.yaml", "-strict-implicit-module-context", "-Xcc", "-Xclang", "-Xcc", "-fbuiltin-headers-in-system-modules")
+          $SwiftArgs += @("-L", "$SwiftResourceDir\$($Platform.ToString().ToLowerInvariant())")
         }
       } else {
         $SwiftArgs += @("-sdk", (Get-PinnedToolchainSDK))
@@ -808,19 +1003,26 @@ function Build-CMakeProject {
 
       # Debug Information
       if ($DebugInfo) {
-        if ($SwiftDebugFormat -eq "dwarf") {
-          $SwiftArgs += @("-g", "-Xlinker", "/DEBUG:DWARF", "-use-ld=lld-link")
+        if ($Platform -eq "Windows") {
+          if ($SwiftDebugFormat -eq "dwarf") {
+            $SwiftArgs += @("-g", "-Xlinker", "/DEBUG:DWARF", "-use-ld=lld-link")
+          } else {
+            $SwiftArgs += @("-g", "-debug-info-format=codeview", "-Xlinker", "-debug")
+          }
         } else {
-          $SwiftArgs += @("-g", "-debug-info-format=codeview", "-Xlinker", "-debug")
+          $SwiftArgs += @("-g")
         }
       } else {
         $SwiftArgs += "-gnone"
       }
-      $SwiftArgs += @("-Xlinker", "/INCREMENTAL:NO")
 
-      # Swift Requries COMDAT folding and de-duplication
-      $SwiftArgs += @("-Xlinker", "/OPT:REF")
-      $SwiftArgs += @("-Xlinker", "/OPT:ICF")
+      if ($Platform -eq "Windows") {
+        $SwiftArgs += @("-Xlinker", "/INCREMENTAL:NO")
+        # Swift Requries COMDAT folding and de-duplication
+        $SwiftArgs += @("-Xlinker", "/OPT:REF")
+        $SwiftArgs += @("-Xlinker", "/OPT:ICF")
+      }
+
       Append-FlagsDefine $Defines CMAKE_Swift_FLAGS $SwiftArgs
 
       # Workaround CMake 3.26+ enabling `-wmo` by default on release builds
@@ -1160,7 +1362,7 @@ function Build-LLVM([Platform]$Platform, $Arch) {
     -Platform $Platform `
     -UseMSVCCompilers C,CXX `
     -Defines @{
-      CMAKE_SYSTEM_NAME = if ($Platform -eq "Windows") { "Windows" } else { "Android" };
+      CMAKE_SYSTEM_NAME = $Platform.ToString();
       LLVM_HOST_TRIPLE = $Arch.LLVMTarget;
     }
 }
@@ -1178,7 +1380,8 @@ function Build-ZLib([Platform]$Platform, $Arch) {
     -BuildTargets default `
     -Defines @{
       BUILD_SHARED_LIBS = "NO";
-      CMAKE_SYSTEM_NAME = if ($Platform -eq "Windows") { "Windows" } else { "Android" };
+      CMAKE_POSITION_INDEPENDENT_CODE = "YES";
+      CMAKE_SYSTEM_NAME = $Platform.ToString();
       INSTALL_BIN_DIR = "$LibraryRoot\zlib-1.3.1\usr\bin\$Platform\$ArchName";
       INSTALL_LIB_DIR = "$LibraryRoot\zlib-1.3.1\usr\lib\$Platform\$ArchName";
     }
@@ -1199,7 +1402,7 @@ function Build-XML2([Platform]$Platform, $Arch) {
       BUILD_SHARED_LIBS = "NO";
       CMAKE_INSTALL_BINDIR = "bin/$Platform/$ArchName";
       CMAKE_INSTALL_LIBDIR = "lib/$Platform/$ArchName";
-      CMAKE_SYSTEM_NAME = if ($Platform -eq "Windows") { "Windows" } else { "Android" };
+      CMAKE_SYSTEM_NAME = $Platform.ToString();
       LIBXML2_WITH_ICONV = "NO";
       LIBXML2_WITH_ICU = "NO";
       LIBXML2_WITH_LZMA = "NO";
@@ -1232,7 +1435,7 @@ function Build-CURL([Platform]$Platform, $Arch) {
       BUILD_SHARED_LIBS = "NO";
       BUILD_TESTING = "NO";
       CMAKE_INSTALL_LIBDIR = "lib/$Platform/$ArchName";
-      CMAKE_SYSTEM_NAME = if ($Platform -eq "Windows") { "Windows" } else { "Android" };
+      CMAKE_SYSTEM_NAME = $Platform.ToString();
       BUILD_CURL_EXE = "NO";
       CURL_CA_BUNDLE = "none";
       CURL_CA_FALLBACK = "NO";
@@ -1328,6 +1531,7 @@ function Build-ICU([Platform]$Platform, $Arch) {
   } else {
     $BuildToolsDefines = @{
       BUILD_TOOLS = "NO";
+      BUILD_DATA = if ($Platform -eq "Android") { "NO" } else { "YES" };
       ICU_TOOLS_DIR = "$($BuildArch.BinaryCache)\windows\icu-69.1"
     }
   }
@@ -1342,13 +1546,23 @@ function Build-ICU([Platform]$Platform, $Arch) {
     -BuildTargets default `
     -Defines ($BuildToolsDefines + @{
       BUILD_SHARED_LIBS = "NO";
-      CMAKE_SYSTEM_NAME = if ($Platform -eq "Windows") { "Windows" } else { "Android" };
+      CMAKE_SYSTEM_NAME = $Platform.ToString();
+      CMAKE_POSITION_INDEPENDENT_CODE = "YES";
       CMAKE_INSTALL_BINDIR = "bin/$Platform/$ArchName";
       CMAKE_INSTALL_LIBDIR = "lib/$Platform/$ArchName";
     })
 }
 
 function Build-Runtime([Platform]$Platform, $Arch) {
+  $PlatformDefines = @{}
+  if ($Platform -eq "Android") {
+    $PlatformDefines += @{
+      LLVM_ENABLE_LIBCXX = "YES";
+      SWIFT_USE_LINKER = "lld";
+    }
+  }
+
+
   Isolate-EnvVars {
     $env:Path = "$($HostArch.BinaryCache)\cmark-gfm-0.29.0.gfm.13\src;$(Get-PinnedToolchainRuntime);${env:Path}"
 
@@ -1364,13 +1578,13 @@ function Build-Runtime([Platform]$Platform, $Arch) {
       -InstallTo "$($Arch.SDKInstallRoot)\usr" `
       -Arch $Arch `
       -Platform $Platform `
-      -CacheScript $SourceCache\swift\cmake\caches\Runtime-Windows-$($Arch.LLVMName).cmake `
+      -CacheScript $SourceCache\swift\cmake\caches\Runtime-$Platform-$($Arch.LLVMName).cmake `
       -UseBuiltCompilers C,CXX,Swift `
       -BuildTargets default `
-      -Defines @{
-        CMAKE_Swift_COMPILER_TARGET = $Arch.LLVMTarget;
+      -Defines ($PlatformDefines + @{
+        CMAKE_Swift_COMPILER_TARGET = $Arch.LLVMTarget.Replace("$AndroidAPILevel", "");
         CMAKE_Swift_COMPILER_WORKS = "YES";
-        CMAKE_SYSTEM_NAME = if ($Platform -eq "Windows") { "Windows" } else { "Android" };
+        CMAKE_SYSTEM_NAME = $Platform.ToString();
         LLVM_DIR = "$(Get-TargetProjectBinaryCache $Arch LLVM)\lib\cmake\llvm";
         SWIFT_ENABLE_EXPERIMENTAL_CONCURRENCY = "YES";
         SWIFT_ENABLE_EXPERIMENTAL_CXX_INTEROP = "YES";
@@ -1378,12 +1592,13 @@ function Build-Runtime([Platform]$Platform, $Arch) {
         SWIFT_ENABLE_EXPERIMENTAL_DISTRIBUTED = "YES";
         SWIFT_ENABLE_EXPERIMENTAL_OBSERVATION = "YES";
         SWIFT_ENABLE_EXPERIMENTAL_STRING_PROCESSING = "YES";
-        SWIFT_ENABLE_SYNCHRONIZATION = "YES";
+        # FIXME: re-enable after https://github.com/apple/swift/issues/74186 is fixed.
+        SWIFT_ENABLE_SYNCHRONIZATION = if (($Platform -eq "Android") -and ($Arch -eq $AndroidARMv7)) { "NO" } else { "YES" };
         SWIFT_NATIVE_SWIFT_TOOLS_PATH = (Join-Path -Path $CompilersBinaryCache -ChildPath "bin");
         SWIFT_PATH_TO_LIBDISPATCH_SOURCE = "$SourceCache\swift-corelibs-libdispatch";
         SWIFT_PATH_TO_STRING_PROCESSING_SOURCE = "$SourceCache\swift-experimental-string-processing";
-        CMAKE_SHARED_LINKER_FLAGS = @("/INCREMENTAL:NO", "/OPT:REF", "/OPT:ICF");
-      }
+        CMAKE_SHARED_LINKER_FLAGS = if ($Platform -eq "Windows") { @("/INCREMENTAL:NO", "/OPT:REF", "/OPT:ICF") } else { @() };
+      })
   }
 
   Invoke-Program $python -c "import plistlib; print(str(plistlib.dumps({ 'DefaultProperties': { 'DEFAULT_USE_RUNTIME': 'MD' } }), encoding='utf-8'))" `
@@ -1435,19 +1650,41 @@ function Build-Foundation([Platform]$Platform, $Arch, [switch]$Test = $false) {
       -UseBuiltCompilers ASM,C,Swift `
       -BuildTargets $Targets `
       -Defines (@{
+        FOUNDATION_BUILD_TOOLS = if ($Platform -eq "Windows") { "YES" } else { "NO" };
         # Turn off safeseh for lld as it has safeseh enabled by default
         # and fails with an ICU data object file icudt69l_dat.obj. This
         # matters to X86 only.
         CMAKE_Swift_FLAGS = if ($Arch -eq $ArchX86) { @("-Xlinker", "/SAFESEH:NO") } else { "" };
         CURL_DIR = "$LibraryRoot\curl-8.5.0\usr\lib\$Platform\$ShortArch\cmake\CURL";
-        ICU_DATA_LIBRARY_RELEASE = "$LibraryRoot\icu-69.1\usr\lib\$Platform\$ShortArch\sicudt69.lib";
-        ICU_I18N_LIBRARY_RELEASE = "$LibraryRoot\icu-69.1\usr\lib\$Platform\$ShortArch\sicuin69.lib";
+        ICU_DATA_LIBRARY_RELEASE = if ($Platform -eq "Windows") {
+          "$LibraryRoot\icu-69.1\usr\lib\$Platform\$ShortArch\sicudt69.lib"
+        } else {
+          "$LibraryRoot\icu-69.1\usr\lib\$Platform\$ShortArch\libicudt69.a"
+        };
+        ICU_I18N_LIBRARY_RELEASE = if ($Platform -eq "Windows") {
+          "$LibraryRoot\icu-69.1\usr\lib\$Platform\$ShortArch\sicuin69.lib"
+        } else {
+          "$LibraryRoot\icu-69.1\usr\lib\$Platform\$ShortArch\libicuin69.a"
+        };
         ICU_ROOT = "$LibraryRoot\icu-69.1\usr";
-        ICU_UC_LIBRARY_RELEASE = "$LibraryRoot\icu-69.1\usr\lib\$Platform\$ShortArch\sicuuc69.lib";
-        LIBXML2_LIBRARY = "$LibraryRoot\libxml2-2.11.5\usr\lib\$Platform\$ShortArch\libxml2s.lib";
+        ICU_INCLUDE_DIR = "$LibraryRoot\icu-69.1\usr\include";
+        ICU_UC_LIBRARY_RELEASE = if ($Platform -eq "Windows") {
+          "$LibraryRoot\icu-69.1\usr\lib\$Platform\$ShortArch\sicuuc69.lib";
+        } else {
+          "$LibraryRoot\icu-69.1\usr\lib\$Platform\$ShortArch\libicuuc69.a"
+        };
+        LIBXML2_LIBRARY = if ($Platform -eq "Windows") {
+          "$LibraryRoot\libxml2-2.11.5\usr\lib\$Platform\$ShortArch\libxml2s.lib";
+        } else {
+          "$LibraryRoot\libxml2-2.11.5\usr\lib\$Platform\$ShortArch\libxml2.a";
+        };
         LIBXML2_INCLUDE_DIR = "$LibraryRoot\libxml2-2.11.5\usr\include\libxml2";
-        LIBXML2_DEFINITIONS = "/DLIBXML_STATIC";
-        ZLIB_LIBRARY = "$LibraryRoot\zlib-1.3.1\usr\lib\$Platform\$ShortArch\zlibstatic.lib";
+        LIBXML2_DEFINITIONS = "-DLIBXML_STATIC";
+        ZLIB_LIBRARY = if ($Platform -eq "Windows") {
+          "$LibraryRoot\zlib-1.3.1\usr\lib\$Platform\$ShortArch\zlibstatic.lib"
+        } else {
+          "$LibraryRoot\zlib-1.3.1\usr\lib\$Platform\$ShortArch\libz.a"
+        };
         ZLIB_INCLUDE_DIR = "$LibraryRoot\zlib-1.3.1\usr\include";
         dispatch_DIR = "$DispatchBinaryCache\cmake\modules";
       } + $TestingDefines)
@@ -1484,11 +1721,12 @@ function Build-XCTest([Platform]$Platform, $Arch, [switch]$Test = $false) {
       -UseBuiltCompilers Swift `
       -BuildTargets $Targets `
       -Defines (@{
+        CMAKE_BUILD_WITH_INSTALL_RPATH = "YES";
         dispatch_DIR = "$DispatchBinaryCache\cmake\modules";
         Foundation_DIR = "$FoundationBinaryCache\cmake\modules";
       } + $TestingDefines)
 
-    $PList = [IO.Path]::Combine($Arch.BinaryCache, "${Platform}.platform".ToLower(), "Info.plist")
+    $PList = Join-Path -Path $Arch.PlatformInstallRoot -ChildPath "Info.plist"
     Invoke-Program $python -c "import plistlib; print(str(plistlib.dumps({ 'DefaultProperties': { 'XCTEST_VERSION': 'development', 'SWIFTC_FLAGS': ['-use-ld=lld'] } }), encoding='utf-8'))" `
       -OutFile "$PList"
   }
@@ -1515,28 +1753,35 @@ function Install-Platform([Platform]$Platform, $Arch) {
   Copy-File "$($Arch.SDKInstallRoot)\usr\share\*.*" $SDKInstallRoot\usr\share\
 
   # Copy SDK libs, placing them in an arch-specific directory
-  $WindowsLibSrc = "$($Arch.SDKInstallRoot)\usr\lib\swift\windows"
-  $WindowsLibDst = "$SDKInstallRoot\usr\lib\swift\windows"
+  $PlatformLibSrc = "$($Arch.SDKInstallRoot)\usr\lib\swift\$($Platform.ToString().ToLowerInvariant())"
+  $PlatformLibDst = "$SDKInstallRoot\usr\lib\swift\$($Platform.ToString().ToLowerInvariant())"
 
-  Copy-File "$WindowsLibSrc\*.lib" "$WindowsLibDst\$($Arch.LLVMName)\"
-  Copy-File "$WindowsLibSrc\$($Arch.LLVMName)\*.lib" "$WindowsLibDst\$($Arch.LLVMName)\"
+  switch ($Platform) {
+    Windows {
+      Copy-File "$PlatformLibSrc\*.lib" "$PlatformLibDst\$($Arch.LLVMName)\"
+      Copy-File "$PlatformLibSrc\$($Arch.LLVMName)\*.lib" "$PlatformLibDst\$($Arch.LLVMName)\"
+    }
+    Android {
+      Copy-File "$PlatformLibSrc\*.so" "$PlatformLibDst\$($Arch.LLVMName)\"
+    }
+  }
 
   # Copy well-structured SDK modules
-  Copy-Directory "$WindowsLibSrc\*.swiftmodule" "$WindowsLibDst\"
+  Copy-Directory "$PlatformLibSrc\*.swiftmodule" "$PlatformLibDst\"
 
   # Copy files from the arch subdirectory, including "*.swiftmodule" which need restructuring
-  Get-ChildItem -Recurse "$WindowsLibSrc\$($Arch.LLVMName)" | ForEach-Object {
+  Get-ChildItem -Recurse "$PlatformLibSrc\$($Arch.LLVMName)" | ForEach-Object {
     if (".swiftmodule", ".swiftdoc", ".swiftinterface" -contains $_.Extension) {
-      $DstDir = "$WindowsLibDst\$($_.BaseName).swiftmodule"
+      $DstDir = "$PlatformLibDst\$($_.BaseName).swiftmodule"
       Copy-File $_.FullName "$DstDir\$($Arch.LLVMTarget)$($_.Extension)"
     } else {
-      Copy-File $_.FullName "$WindowsLibDst\$($Arch.LLVMName)\"
+      Copy-File $_.FullName "$PlatformLibDst\$($Arch.LLVMName)\"
     }
   }
 
   # Copy the CxxShim module
   foreach ($Source in ("libcxxshim.h", "libcxxshim.modulemap", "libcxxstdlibshim.h")) {
-    Copy-File "$WindowsLibSrc\$Source" "$WindowsLibDst"
+    Copy-File "$PlatformLibSrc\$Source" "$PlatformLibDst"
   }
 
   # Copy plist files (same across architectures)
@@ -1551,11 +1796,11 @@ function Install-Platform([Platform]$Platform, $Arch) {
       Copy-File "$($Arch.XCTestInstallRoot)\usr\lib\swift\windows\XCTest.lib" "$XCTestInstallRoot\usr\lib\swift\windows\$($Arch.LLVMName)\"
     }
     default {
-      Copy-File "$($Arch.XCTestInstallRoot)\usr\lib\libXCTest.so" "$XCTestInstallRoot\usr\lib\$($Arch.BinaryDir)\"
+      Copy-File "$($Arch.XCTestInstallRoot)\usr\lib\swift\$($Platform.ToString().ToLowerInvariant())\libXCTest.so" "$XCTestInstallRoot\usr\lib\$($Arch.BinaryDir)\"
     }
   }
-  Copy-File "$($Arch.XCTestInstallRoot)\usr\lib\swift\$($Platform.ToString().ToLower())\$($Arch.LLVMName)\XCTest.swiftmodule" "$XCTestInstallRoot\usr\lib\swift\$($Platform.ToString().ToLower())\XCTest.swiftmodule\$($Arch.LLVMTarget).swiftmodule"
-  Copy-File "$($Arch.XCTestInstallRoot)\usr\lib\swift\$($Platform.ToString().ToLower())\$($Arch.LLVMName)\XCTest.swiftdoc" "$XCTestInstallRoot\usr\lib\swift\$($Platform.ToString().ToLower())\XCTest.swiftmodule\$($Arch.LLVMTarget).swiftdoc"
+  Copy-File "$($Arch.XCTestInstallRoot)\usr\lib\swift\$($Platform.ToString().ToLowerInvariant())\$($Arch.LLVMName)\XCTest.swiftmodule" "$XCTestInstallRoot\usr\lib\swift\$($Platform.ToString().ToLowerInvariant())\XCTest.swiftmodule\$($Arch.LLVMTarget).swiftmodule"
+  Copy-File "$($Arch.XCTestInstallRoot)\usr\lib\swift\$($Platform.ToString().ToLowerInvariant())\$($Arch.LLVMName)\XCTest.swiftdoc" "$XCTestInstallRoot\usr\lib\swift\$($Platform.ToString().ToLowerInvariant())\XCTest.swiftmodule\$($Arch.LLVMTarget).swiftdoc"
 }
 
 function Build-SQLite($Arch) {
@@ -1611,8 +1856,9 @@ function Build-System($Arch) {
     -Bin (Get-HostProjectBinaryCache System) `
     -InstallTo "$($Arch.ToolchainInstallRoot)\usr" `
     -Arch $Arch `
+    -Platform Windows `
     -UseBuiltCompilers C,Swift `
-    -SwiftSDK ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk")) `
+    -SwiftSDK (Get-HostSwiftSDK) `
     -BuildTargets default `
     -Defines @{
       BUILD_SHARED_LIBS = "YES";
@@ -1630,8 +1876,9 @@ function Build-ToolsSupportCore($Arch) {
     -Bin (Get-HostProjectBinaryCache ToolsSupportCore) `
     -InstallTo "$($Arch.ToolchainInstallRoot)\usr" `
     -Arch $Arch `
+    -Platform Windows `
     -UseBuiltCompilers C,Swift `
-    -SwiftSDK ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk")) `
+    -SwiftSDK (Get-HostSwiftSDK) `
     -BuildTargets default `
     -Defines @{
       BUILD_SHARED_LIBS = "YES";
@@ -1666,9 +1913,10 @@ function Build-LLBuild($Arch, [switch]$Test = $false) {
       -Bin (Get-HostProjectBinaryCache LLBuild) `
       -InstallTo "$($Arch.ToolchainInstallRoot)\usr" `
       -Arch $Arch `
+      -Platform Windows `
       -UseMSVCCompilers CXX `
       -UseBuiltCompilers Swift `
-      -SwiftSDK ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk")) `
+      -SwiftSDK (Get-HostSwiftSDK) `
       -BuildTargets $Targets `
       -Defines ($TestingDefines + @{
         BUILD_SHARED_LIBS = "YES";
@@ -1684,8 +1932,9 @@ function Build-Yams($Arch) {
     -Src $SourceCache\Yams `
     -Bin (Get-HostProjectBinaryCache Yams) `
     -Arch $Arch `
+    -Platform Windows `
     -UseBuiltCompilers C,Swift `
-    -SwiftSDK ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk")) `
+    -SwiftSDK (Get-HostSwiftSDK) `
     -BuildTargets default `
     -Defines @{
       BUILD_SHARED_LIBS = "NO";
@@ -1699,8 +1948,9 @@ function Build-ArgumentParser($Arch) {
     -Bin (Get-HostProjectBinaryCache ArgumentParser) `
     -InstallTo "$($Arch.ToolchainInstallRoot)\usr" `
     -Arch $Arch `
+    -Platform Windows `
     -UseBuiltCompilers Swift `
-    -SwiftSDK ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk")) `
+    -SwiftSDK (Get-HostSwiftSDK) `
     -BuildTargets default `
     -Defines @{
       BUILD_SHARED_LIBS = "YES";
@@ -1714,8 +1964,9 @@ function Build-Driver($Arch) {
     -Bin (Get-HostProjectBinaryCache Driver) `
     -InstallTo "$($Arch.ToolchainInstallRoot)\usr" `
     -Arch $Arch `
+    -Platform Windows `
     -UseBuiltCompilers C,CXX,Swift `
-    -SwiftSDK ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk")) `
+    -SwiftSDK (Get-HostSwiftSDK) `
     -BuildTargets default `
     -Defines @{
       BUILD_SHARED_LIBS = "YES";
@@ -1739,8 +1990,9 @@ function Build-Crypto($Arch) {
     -Src $SourceCache\swift-crypto `
     -Bin (Get-HostProjectBinaryCache Crypto) `
     -Arch $Arch `
+    -Platform Windows `
     -UseBuiltCompilers Swift `
-    -SwiftSDK ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk")) `
+    -SwiftSDK (Get-HostSwiftSDK) `
     -BuildTargets default `
     -Defines @{
       BUILD_SHARED_LIBS = "NO";
@@ -1753,8 +2005,9 @@ function Build-Collections($Arch) {
     -Bin (Get-HostProjectBinaryCache Collections) `
     -InstallTo "$($Arch.ToolchainInstallRoot)\usr" `
     -Arch $Arch `
+    -Platform Windows `
     -UseBuiltCompilers C,Swift `
-    -SwiftSDK ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk")) `
+    -SwiftSDK (Get-HostSwiftSDK) `
     -BuildTargets default `
     -Defines @{
       BUILD_SHARED_LIBS = "YES";
@@ -1767,7 +2020,7 @@ function Build-ASN1($Arch) {
     -Bin (Get-HostProjectBinaryCache ASN1) `
     -Arch $Arch `
     -UseBuiltCompilers C,Swift `
-    -SwiftSDK ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk")) `
+    -SwiftSDK (Get-HostSwiftSDK) `
     -BuildTargets default `
     -Defines @{
       BUILD_SHARED_LIBS = "NO";
@@ -1779,8 +2032,9 @@ function Build-Certificates($Arch) {
     -Src $SourceCache\swift-certificates `
     -Bin (Get-HostProjectBinaryCache Certificates) `
     -Arch $Arch `
+    -Platform Windows `
     -UseBuiltCompilers Swift `
-    -SwiftSDK ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk")) `
+    -SwiftSDK (Get-HostSwiftSDK) `
     -BuildTargets default `
     -Defines @{
       BUILD_SHARED_LIBS = "NO";
@@ -1801,8 +2055,9 @@ function Build-PackageManager($Arch) {
     -Bin (Get-HostProjectBinaryCache PackageManager) `
     -InstallTo "$($Arch.ToolchainInstallRoot)\usr" `
     -Arch $Arch `
+    -Platform Windows `
     -UseBuiltCompilers C,Swift `
-    -SwiftSDK ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk")) `
+    -SwiftSDK (Get-HostSwiftSDK) `
     -BuildTargets default `
     -Defines @{
       BUILD_SHARED_LIBS = "YES";
@@ -1828,8 +2083,9 @@ function Build-Markdown($Arch) {
     -Bin (Get-HostProjectBinaryCache Markdown) `
     -InstallTo "$($Arch.ToolchainInstallRoot)\usr" `
     -Arch $Arch `
+    -Platform Windows `
     -UseBuiltCompilers C,Swift `
-    -SwiftSDK ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk")) `
+    -SwiftSDK (Get-HostSwiftSDK) `
     -BuildTargets default `
     -Defines @{
       BUILD_SHARED_LIBS = "NO";
@@ -1844,9 +2100,10 @@ function Build-Format($Arch) {
     -Bin (Get-HostProjectBinaryCache Format) `
     -InstallTo "$($Arch.ToolchainInstallRoot)\usr" `
     -Arch $Arch `
+    -Platform Windows `
     -UseMSVCCompilers C `
     -UseBuiltCompilers Swift `
-    -SwiftSDK ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk")) `
+    -SwiftSDK (Get-HostSwiftSDK) `
     -BuildTargets default `
     -Defines @{
       BUILD_SHARED_LIBS = "YES";
@@ -1858,12 +2115,13 @@ function Build-Format($Arch) {
 }
 
 function Build-IndexStoreDB($Arch) {
-  $SDKInstallRoot = ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk"))
+  $SDKInstallRoot = (Get-HostSwiftSDK);
 
   Build-CMakeProject `
     -Src $SourceCache\indexstore-db `
     -Bin (Get-HostProjectBinaryCache IndexStoreDB) `
     -Arch $Arch `
+    -Platform Windows `
     -UseBuiltCompilers C,CXX,Swift `
     -SwiftSDK $SDKInstallRoot `
     -BuildTargets default `
@@ -1880,8 +2138,9 @@ function Build-SourceKitLSP($Arch) {
     -Bin (Get-HostProjectBinaryCache SourceKitLSP) `
     -InstallTo "$($Arch.ToolchainInstallRoot)\usr" `
     -Arch $Arch `
+    -Platform Windows `
     -UseBuiltCompilers C,Swift `
-    -SwiftSDK ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk")) `
+    -SwiftSDK (Get-HostSwiftSDK) `
     -BuildTargets default `
     -Defines @{
       SwiftSyntax_DIR = (Get-HostProjectCMakeModules Compilers);
@@ -1918,7 +2177,7 @@ function Install-HostToolchain() {
 
 function Build-Inspect() {
   $OutDir = Join-Path -Path $HostArch.BinaryCache -ChildPath swift-inspect
-  $SDKInstallRoot = ([IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "Windows.platform", "Developer", "SDKs", "Windows.sdk")) `
+  $SDKInstallRoot = (Get-HostSwiftSDK) `
 
   Isolate-EnvVars {
     $env:SWIFTCI_USE_LOCAL_DEPS=1
@@ -2056,6 +2315,20 @@ if (-not $SkipBuild) {
     Invoke-BuildStep Build-Foundation Windows $Arch
     Invoke-BuildStep Build-XCTest Windows $Arch
   }
+
+   foreach ($Arch in $AndroidSDKArchs) {
+     Invoke-BuildStep Build-ZLib Android $Arch
+     Invoke-BuildStep Build-XML2 Android $Arch
+     Invoke-BuildStep Build-CURL Android $Arch
+     Invoke-BuildStep Build-ICU Android $Arch
+     Invoke-BuildStep Build-LLVM Android $Arch
+
+     # Build platform: SDK, Redist and XCTest
+     Invoke-BuildStep Build-Runtime Android $Arch
+     Invoke-BuildStep Build-Dispatch Android $Arch
+     Invoke-BuildStep Build-Foundation Android $Arch
+     Invoke-BuildStep Build-XCTest Android $Arch
+   }
 }
 
 if (-not $ToBatch) {
@@ -2070,6 +2343,10 @@ if (-not $ToBatch) {
   foreach ($Arch in $WindowsSDKArchs) {
     Install-Platform Windows $Arch
   }
+
+  foreach ($Arch in $AndroidSDKArchs) {
+    Install-Platform Android $Arch
+  }
 }
 
 if (-not $SkipBuild) {