@@ -710,6 +710,11 @@ process and user.
    :func:`socket.gethostname`  or even
    ``socket.gethostbyaddr(socket.gethostname())``.
 
+   On macOS, iOS and Android, this returns the *kernel* name and version (i.e.,
+   ``'Darwin'`` on macOS and iOS; ``'Linux'`` on Android). :func:`platform.uname()`
+   can be used to get the user-facing operating system name and version on iOS and
+   Android.
+
    .. availability:: recent flavors of Unix.
 
    .. versionchanged:: 3.3
 
@@ -148,6 +148,9 @@ Cross Platform
    Returns the system/OS name, such as ``'Linux'``, ``'Darwin'``, ``'Java'``,
    ``'Windows'``. An empty string is returned if the value cannot be determined.
 
+   On iOS and Android, this returns the user-facing OS name (i.e, ``'iOS``,
+   ``'iPadOS'`` or ``'Android'``). To obtain the kernel name (``'Darwin'`` or
+   ``'Linux'``), use :func:`os.uname()`.
 
 .. function:: system_alias(system, release, version)
 
@@ -161,6 +164,8 @@ Cross Platform
    Returns the system's release version, e.g. ``'#3 on degas'``. An empty string is
    returned if the value cannot be determined.
 
+   On iOS and Android, this is the user-facing OS version. To obtain the
+   Darwin or Linux kernel version, use :func:`os.uname()`.
 
 .. function:: uname()
 
@@ -230,7 +235,6 @@ Windows Platform
 macOS Platform
 --------------
 
-
 .. function:: mac_ver(release='', versioninfo=('','',''), machine='')
 
    Get macOS version information and return it as tuple ``(release, versioninfo,
@@ -240,6 +244,24 @@ macOS Platform
    Entries which cannot be determined are set to ``''``.  All tuple entries are
    strings.
 
+iOS Platform
+------------
+
+.. function:: ios_ver(system='', release='', model='', is_simulator=False)
+
+   Get iOS version information and return it as a
+   :func:`~collections.namedtuple` with the following attributes:
+
+   * ``system`` is the OS name; either ``'iOS'`` or ``'iPadOS'``.
+   * ``release`` is the iOS version number as a string (e.g., ``'17.2'``).
+   * ``model`` is the device model identifier; this will be a string like
+     ``'iPhone13,2'`` for a physical device, or ``'iPhone'`` on a simulator.
+   * ``is_simulator`` is a boolean describing if the app is running on a
+     simulator or a physical device.
+
+   Entries which cannot be determined are set to the defaults given as
+   parameters.
+
 
 Unix Platforms
 --------------
 
@@ -33,6 +33,13 @@ allow the remote browser to maintain its own windows on the display.  If remote
 browsers are not available on Unix, the controlling process will launch a new
 browser and wait.
 
+On iOS, the :envvar:`BROWSER` environment variable, as well as any arguments
+controlling autoraise, browser preference, and new tab/window creation will be
+ignored. Web pages will *always* be opened in the user's preferred browser, in
+a new tab, with the browser being brought to the foreground. The use of the
+:mod:`webbrowser` module on iOS requires the :mod:`ctypes` module. If
+:mod:`ctypes` isn't available, calls to :func:`.open` will fail.
+
 The script :program:`webbrowser` can be used as a command-line interface for the
 module. It accepts a URL as the argument. It accepts the following optional
 parameters: ``-n`` opens the URL in a new browser window, if possible;
@@ -155,6 +162,8 @@ for the controller classes, all defined in this module.
 +------------------------+-----------------------------------------+-------+
 | ``'chromium-browser'`` | :class:`Chromium('chromium-browser')`   |       |
 +------------------------+-----------------------------------------+-------+
+| ``'iosbrowser'``       | ``IOSBrowser``                          | \(4)  |
++------------------------+-----------------------------------------+-------+
 
 Notes:
 
@@ -169,11 +178,18 @@ Notes:
    Only on Windows platforms.
 
 (3)
-   Only on macOS platform.
+   Only on macOS.
+
+(4)
+   Only on iOS.
+
 
 .. versionadded:: 3.3
    Support for Chrome/Chromium has been added.
 
+.. versionchanged:: 3.13
+   Support for iOS has been added.
+
 Here are some simple examples::
 
    url = 'https://docs.python.org/'
 
@@ -0,0 +1,71 @@
+import sys
+try:
+    from ctypes import cdll, c_void_p, c_char_p, util
+except ImportError:
+    # ctypes is an optional module. If it's not present, we're limited in what
+    # we can tell about the system, but we don't want to prevent the module
+    # from working.
+    print("ctypes isn't available; iOS system calls will not be available")
+    objc = None
+else:
+    # ctypes is available. Load the ObjC library, and wrap the objc_getClass,
+    # sel_registerName methods
+    lib = util.find_library("objc")
+    if lib is None:
+        # Failed to load the objc library
+        raise RuntimeError("ObjC runtime library couldn't be loaded")
+
+    objc = cdll.LoadLibrary(lib)
+    objc.objc_getClass.restype = c_void_p
+    objc.objc_getClass.argtypes = [c_char_p]
+    objc.sel_registerName.restype = c_void_p
+    objc.sel_registerName.argtypes = [c_char_p]
+
+
+def get_platform_ios():
+    # Determine if this is a simulator using the multiarch value
+    is_simulator = sys.implementation._multiarch.endswith("simulator")
+
+    # We can't use ctypes; abort
+    if not objc:
+        return None
+
+    # Most of the methods return ObjC objects
+    objc.objc_msgSend.restype = c_void_p
+    # All the methods used have no arguments.
+    objc.objc_msgSend.argtypes = [c_void_p, c_void_p]
+
+    # Equivalent of:
+    #   device = [UIDevice currentDevice]
+    UIDevice = objc.objc_getClass(b"UIDevice")
+    SEL_currentDevice = objc.sel_registerName(b"currentDevice")
+    device = objc.objc_msgSend(UIDevice, SEL_currentDevice)
+
+    # Equivalent of:
+    #   device_systemVersion = [device systemVersion]
+    SEL_systemVersion = objc.sel_registerName(b"systemVersion")
+    device_systemVersion = objc.objc_msgSend(device, SEL_systemVersion)
+
+    # Equivalent of:
+    #   device_systemName = [device systemName]
+    SEL_systemName = objc.sel_registerName(b"systemName")
+    device_systemName = objc.objc_msgSend(device, SEL_systemName)
+
+    # Equivalent of:
+    #   device_model = [device model]
+    SEL_model = objc.sel_registerName(b"model")
+    device_model = objc.objc_msgSend(device, SEL_model)
+
+    # UTF8String returns a const char*;
+    SEL_UTF8String = objc.sel_registerName(b"UTF8String")
+    objc.objc_msgSend.restype = c_char_p
+
+    # Equivalent of:
+    #   system = [device_systemName UTF8String]
+    #   release = [device_systemVersion UTF8String]
+    #   model = [device_model UTF8String]
+    system = objc.objc_msgSend(device_systemName, SEL_UTF8String).decode()
+    release = objc.objc_msgSend(device_systemVersion, SEL_UTF8String).decode()
+    model = objc.objc_msgSend(device_model, SEL_UTF8String).decode()
+
+    return system, release, model, is_simulator
@@ -5,6 +5,9 @@
 from io import BytesIO
 from test.support import run_unittest
 
+if sys.platform != 'win32':
+    raise unittest.SkipTest("Cygwin tests only needed on Windows")
+
 from distutils import cygwinccompiler
 from distutils.cygwinccompiler import (check_config_h,
                                        CONFIG_H_OK, CONFIG_H_NOTOK,
 
@@ -10,7 +10,7 @@
 from distutils import sysconfig
 from distutils.ccompiler import get_default_compiler
 from distutils.tests import support
-from test.support import run_unittest, swap_item
+from test.support import is_apple_mobile, requires_subprocess, run_unittest, swap_item
 from test.support.os_helper import TESTFN
 from test.support.warnings_helper import check_warnings
 
@@ -32,6 +32,7 @@ def cleanup_testfn(self):
         elif os.path.isdir(TESTFN):
             shutil.rmtree(TESTFN)
 
+    @unittest.skipIf(is_apple_mobile, "Header files not distributed with Apple mobile")
     def test_get_config_h_filename(self):
         config_h = sysconfig.get_config_h_filename()
         self.assertTrue(os.path.isfile(config_h), config_h)
@@ -48,6 +49,7 @@ def test_get_config_vars(self):
         self.assertIsInstance(cvars, dict)
         self.assertTrue(cvars)
 
+    @unittest.skipIf(is_apple_mobile, "Header files not distributed with Apple mobile")
     def test_srcdir(self):
         # See Issues #15322, #15364.
         srcdir = sysconfig.get_config_var('srcdir')
@@ -247,6 +249,7 @@ def test_SO_in_vars(self):
         self.assertIsNotNone(vars['SO'])
         self.assertEqual(vars['SO'], vars['EXT_SUFFIX'])
 
+    @requires_subprocess()
     def test_customize_compiler_before_get_config_vars(self):
         # Issue #21923: test that a Distribution compiler
         # instance can be called without an explicit call to
 
@@ -270,9 +270,9 @@ def find_library_file(self, dirs, lib, debug=0):
         static_f = self.library_filename(lib, lib_type='static')
 
         if sys.platform == 'darwin':
-            # On OSX users can specify an alternate SDK using
-            # '-isysroot', calculate the SDK root if it is specified
-            # (and use it further on)
+            # On macOS users can specify an alternate SDK using
+            # '-isysroot <path>' or --sysroot=<path>, calculate the SDK root
+            # if it is specified (and use it further on)
             #
             # Note that, as of Xcode 7, Apple SDKs may contain textual stub
             # libraries with .tbd extensions rather than the normal .dylib
@@ -291,12 +291,14 @@ def find_library_file(self, dirs, lib, debug=0):
             cflags = sysconfig.get_config_var('CFLAGS')
             m = re.search(r'-isysroot\s*(\S+)', cflags)
             if m is None:
-                sysroot = _osx_support._default_sysroot(sysconfig.get_config_var('CC'))
+                m = re.search(r'--sysroot=(\S+)', cflags)
+                if m is None:
+                    sysroot = _osx_support._default_sysroot(sysconfig.get_config_var('CC'))
+                else:
+                    sysroot = m.group(1)
             else:
                 sysroot = m.group(1)
 
-
-
         for dir in dirs:
             shared = os.path.join(dir, shared_f)
             dylib = os.path.join(dir, dylib_f)
 
@@ -89,10 +89,25 @@ def get_host_platform():
         if m:
             release = m.group()
     elif osname[:6] == "darwin":
-        import _osx_support, distutils.sysconfig
-        osname, release, machine = _osx_support.get_platform_osx(
-                                        distutils.sysconfig.get_config_vars(),
-                                        osname, release, machine)
+        import distutils.sysconfig
+        config_vars = distutils.sysconfig.get_config_vars()
+        if sys.platform == "ios":
+            release = config_vars.get("IPHONEOS_DEPLOYMENT_TARGET", "13.0")
+            osname = sys.platform
+            machine = sys.implementation._multiarch
+        elif sys.platform == "tvos":
+            release = config_vars.get("TVOS_DEPLOYMENT_TARGET", "9.0")
+            osname = sys.platform
+            machine = sys.implementation._multiarch
+        elif sys.platform == "watchos":
+            release = config_vars.get("WATCHOS_DEPLOYMENT_TARGET", "4.0")
+            osname = sys.platform
+            machine = sys.implementation._multiarch
+        else:
+            import _osx_support
+            osname, release, machine = _osx_support.get_platform_osx(
+                                            config_vars,
+                                            osname, release, machine)
 
     return "%s-%s-%s" % (osname, release, machine)
 
@@ -170,7 +185,7 @@ def check_environ ():
     if _environ_checked:
         return
 
-    if os.name == 'posix' and 'HOME' not in os.environ:
+    if os.name == 'posix' and 'HOME' not in os.environ and sys.platform not in {"ios", "tvos", "watchos"}:
         try:
             import pwd
             os.environ['HOME'] = pwd.getpwuid(os.getuid())[5]
 
@@ -62,6 +62,7 @@ def test_load_grammar_from_pickle(self):
             shutil.rmtree(tmpdir)
 
     @unittest.skipIf(sys.executable is None, 'sys.executable required')
+    @test.support.requires_subprocess()
     def test_load_grammar_from_subprocess(self):
         tmpdir = tempfile.mkdtemp()
         tmpsubdir = os.path.join(tmpdir, 'subdir')
 
@@ -449,6 +449,30 @@ def mac_ver(release='', versioninfo=('', '', ''), machine=''):
     # If that also doesn't work return the default values
     return release, versioninfo, machine
 
+
+# A namedtuple for iOS version information.
+IOSVersionInfo = collections.namedtuple(
+    "IOSVersionInfo",
+    ["system", "release", "model", "is_simulator"]
+)
+
+
+def ios_ver(system="", release="", model="", is_simulator=False):
+    """Get iOS version information, and return it as a namedtuple:
+        (system, release, model, is_simulator).
+
+    If values can't be determined, they are set to values provided as
+    parameters.
+    """
+    if sys.platform == "ios":
+        import _ios_support
+        result = _ios_support.get_platform_ios()
+        if result is not None:
+            return IOSVersionInfo(*result)
+
+    return IOSVersionInfo(system, release, model, is_simulator)
+
+
 def _java_getprop(name, default):
 
     from java.lang import System
@@ -564,7 +588,7 @@ def _platform(*args):
         if cleaned == platform:
             break
         platform = cleaned
-    while platform[-1] == '-':
+    while platform and platform[-1] == '-':
         platform = platform[:-1]
 
     return platform
@@ -605,7 +629,7 @@ def _syscmd_file(target, default=''):
         default in case the command should fail.
 
     """
-    if sys.platform in ('dos', 'win32', 'win16'):
+    if sys.platform in {'dos', 'win32', 'win16', 'ios', 'tvos', 'watchos'}:
         # XXX Others too ?
         return default
 
@@ -744,6 +768,14 @@ def get_OpenVMS():
             csid, cpu_number = vms_lib.getsyi('SYI$_CPU', 0)
             return 'Alpha' if cpu_number >= 128 else 'VAX'
 
+    # On the iOS simulator, os.uname returns the architecture as uname.machine.
+    # On device it returns the model name for some reason; but there's only one
+    # CPU architecture for iOS devices, so we know the right answer.
+    def get_ios():
+        if sys.implementation._multiarch.endswith("simulator"):
+            return os.uname().machine
+        return 'arm64'
+
     def from_subprocess():
         """
         Fall back to `uname -p`
@@ -893,6 +925,10 @@ def uname():
         system = 'Windows'
         release = 'Vista'
 
+    # Normalize responses on iOS
+    if sys.platform == 'ios':
+        system, release, _, _ = ios_ver()
+
     vals = system, node, release, version, machine
     # Replace 'unknown' values with the more portable ''
     _uname_cache = uname_result(*map(_unknown_as_blank, vals))
@@ -1205,11 +1241,14 @@ def platform(aliased=0, terse=0):
         system, release, version = system_alias(system, release, version)
 
     if system == 'Darwin':
-        # macOS (darwin kernel)
-        macos_release = mac_ver()[0]
-        if macos_release:
-            system = 'macOS'
-            release = macos_release
+        # macOS and iOS both report as a "Darwin" kernel
+        if sys.platform == "ios":
+            system, release, _, _ = ios_ver()
+        else:
+            macos_release = mac_ver()[0]
+            if macos_release:
+                system = 'macOS'
+                release = macos_release
 
     if system == 'Windows':
         # MS platforms