diff --git a/Src/IronPython.Modules/_multiprocessing.cs b/Src/IronPython.Modules/_multiprocessing.cs
new file mode 100644
index 000000000..2be9ac543
--- /dev/null
+++ b/Src/IronPython.Modules/_multiprocessing.cs
@@ -0,0 +1,49 @@
+using Microsoft.Win32.SafeHandles;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net.Sockets;
+using System.Runtime.InteropServices;
+
+using IronPython.Runtime;
+
+[assembly: PythonModule("_multiprocessing_ipy", typeof(IronPython.Modules.MultiProcessing))]
+namespace IronPython.Modules {
+    public static class MultiProcessing {
+        [DllImport("ws2_32.dll", ExactSpelling = true, SetLastError = true)]
+        private static extern SocketError closesocket([In] IntPtr socketHandle);
+
+        public static object closesocket(int handle) {
+            var error = closesocket(new IntPtr(handle));
+            // TODO: raise error
+            return null;
+        }
+
+        [DllImport("ws2_32.dll", SetLastError = true)]
+        private static extern int recv(
+                                     [In] IntPtr socketHandle,
+                                     [In] byte[] pinnedBuffer,
+                                     [In] int len,
+                                     [In] SocketFlags socketFlags
+                                     );
+
+        public static IList<byte> recv(int handle, int size) {
+            var buf = new byte[size];
+            recv(new IntPtr(handle), buf, size, 0);
+            return buf;
+        }
+
+        [DllImport("ws2_32.dll", SetLastError = true)]
+        private static extern int send(
+                                         [In] IntPtr socketHandle,
+                                         [In] byte[] pinnedBuffer,
+                                         [In] int len,
+                                         [In] SocketFlags socketFlags
+                                         );
+
+        public static int send(int handle, [BytesConversion]IList<byte> buf) {
+            return send(new IntPtr(handle), buf.ToArray(), buf.Count, 0);
+        }
+
+    }
+}
diff --git a/Src/IronPython.Modules/_multiprocessing_win32.cs b/Src/IronPython.Modules/_multiprocessing_win32.cs
new file mode 100644
index 000000000..93acf639a
--- /dev/null
+++ b/Src/IronPython.Modules/_multiprocessing_win32.cs
@@ -0,0 +1,39 @@
+using IronPython.Runtime;
+using Microsoft.Win32.SafeHandles;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.InteropServices;
+using System.Text;
+using System.Threading.Tasks;
+
+[assembly: PythonModule("_multiprocessing_win32", typeof(IronPython.Modules.MultiProcessingWin32))]
+namespace IronPython.Modules {
+    public static class MultiProcessingWin32 {
+        public const int WAIT_OBJECT_0 = 0;
+        public const int WAIT_ABANDONED_0 = 0x80;
+        public const int WAIT_TIMEOUT = 0x102;
+        public const int INFINITE = -1;
+
+        public const int ERROR_IO_PENDING = 997;
+        public const int ERROR_MORE_DATA = 0xEA;
+        public const int ERROR_BROKEN_PIPE = 0x6D;
+
+        [return: MarshalAs(UnmanagedType.Bool)]
+        [DllImport("kernel32.dll", SetLastError = true, EntryPoint = "CloseHandle")]
+        public static extern bool CloseHandle(IntPtr hObject);
+
+        [DllImport("kernel32.dll", SetLastError = true)]
+        public static extern int WriteFile(SafeFileHandle handle, byte[] bytes, int numBytesToWrite, out int numBytesWritten, IntPtr mustBeZero);
+
+        [DllImport("kernel32.dll", SetLastError = true)]
+        public static extern int ReadFile(SafeFileHandle handle, byte[] bytes, int numBytesToRead, out int numBytesRead, IntPtr mustBeZero);
+
+        [DllImport("kernel32.dll", SetLastError = true, ExactSpelling = true)]
+        public static extern int WaitForMultipleObjects(uint handle, IntPtr[] handles, bool waitAll, uint milliseconds);
+
+        [DllImport("kernel32.dll")]
+        public static extern void ExitProcess(uint uExitCode);
+    }
+
+}
diff --git a/Src/StdLib/Lib/multiprocessing/connection.py b/Src/StdLib/Lib/multiprocessing/connection.py
index 645a26f06..0ac380969 100644
--- a/Src/StdLib/Lib/multiprocessing/connection.py
+++ b/Src/StdLib/Lib/multiprocessing/connection.py
@@ -42,6 +42,8 @@
 import tempfile
 import itertools
 
+is_win32 = sys.platform == "win32" or sys.platform == "cli" and os.name == "nt"
+
 import _multiprocessing
 from multiprocessing import current_process, AuthenticationError
 from multiprocessing.util import get_temp_dir, Finalize, sub_debug, debug
@@ -65,7 +67,7 @@
     default_family = 'AF_UNIX'
     families += ['AF_UNIX']
 
-if sys.platform == 'win32':
+if is_win32:
     default_family = 'AF_PIPE'
     families += ['AF_PIPE']
 
@@ -178,7 +180,7 @@ def Client(address, family=None, authkey=None):
     return c
 
 
-if sys.platform != 'win32':
+if not is_win32:
 
     def Pipe(duplex=True):
         '''
@@ -326,7 +328,7 @@ def SocketClient(address):
 # Definitions for connections based on named pipes
 #
 
-if sys.platform == 'win32':
+if is_win32:
 
     class PipeListener(object):
         '''
diff --git a/Src/StdLib/Lib/multiprocessing/forking.py b/Src/StdLib/Lib/multiprocessing/forking.py
index 9412eb1ef..9a174c2d1 100644
--- a/Src/StdLib/Lib/multiprocessing/forking.py
+++ b/Src/StdLib/Lib/multiprocessing/forking.py
@@ -37,6 +37,8 @@
 import signal
 import errno
 
+is_win32 = sys.platform == "win32" or sys.platform == "cli" and os.name == "nt"
+
 from multiprocessing import util, process
 
 __all__ = ['Popen', 'assert_spawning', 'exit', 'duplicate', 'close', 'ForkingPickler']
@@ -56,16 +58,7 @@ def assert_spawning(self):
 # Try making some callable types picklable
 #
 
-from pickle import Pickler
-class ForkingPickler(Pickler):
-    dispatch = Pickler.dispatch.copy()
-
-    @classmethod
-    def register(cls, type, reduce):
-        def dispatcher(self, obj):
-            rv = reduce(obj)
-            self.save_reduce(obj=obj, *rv)
-        cls.dispatch[type] = dispatcher
+from _multiprocessing import ForkingPickler
 
 def _reduce_method(m):
     if m.im_self is None:
@@ -99,7 +92,7 @@ def _rebuild_partial(func, args, keywords):
 # Unix
 #
 
-if sys.platform != 'win32':
+if not is_win32:
     import time
 
     exit = os._exit
@@ -203,7 +196,7 @@ def dump(obj, file, protocol=None):
     #
 
     TERMINATE = 0x10000
-    WINEXE = (sys.platform == 'win32' and getattr(sys, 'frozen', False))
+    WINEXE = (is_win32 and getattr(sys, 'frozen', False))
     WINSERVICE = sys.executable.lower().endswith("pythonservice.exe")
 
     exit = win32.ExitProcess