diff --git a/IPython/core/prompts.py b/IPython/core/prompts.py
index 1aeb5c1..473a591 100644
--- a/IPython/core/prompts.py
+++ b/IPython/core/prompts.py
@@ -147,7 +147,10 @@ HOME = os.path.realpath(HOME)
 USER           = py3compat.str_to_unicode(os.environ.get("USER",''))
 HOSTNAME       = py3compat.str_to_unicode(socket.gethostname())
 HOSTNAME_SHORT = HOSTNAME.split(".")[0]
-ROOT_SYMBOL    = "#" if (os.name=='nt' or os.getuid()==0) else "$"
+
+# IronPython doesn't currently have os.getuid() even if 
+# os.name == 'posix'; 2/8/2014
+ROOT_SYMBOL    = "#" if (os.name=='nt' or sys.platform=='cli' or os.getuid()==0) else "$"
 
 prompt_abbreviations = {
     # Prompt/history count
diff --git a/IPython/external/decorator/_decorator.py b/IPython/external/decorator/_decorator.py
index ed37b96..ef56922 100644
--- a/IPython/external/decorator/_decorator.py
+++ b/IPython/external/decorator/_decorator.py
@@ -30,6 +30,9 @@
 """
 Decorator module, see http://pypi.python.org/pypi/decorator
 for the documentation.
+
+NOTE: this is an IPython-patched version to work on IronPython. See
+      FIXED comment below.
 """
 from __future__ import print_function
 
@@ -139,7 +142,12 @@ class FunctionMaker(object):
         func.__defaults__ = getattr(self, 'defaults', ())
         func.__kwdefaults__ = getattr(self, 'kwonlydefaults', None)
         func.__annotations__ = getattr(self, 'annotations', None)
-        callermodule = sys._getframe(3).f_globals.get('__name__', '?')
+        # FIXED: The following is try/excepted in IPython to work 
+        # with IronPython.
+        try:
+            callermodule = sys._getframe(3).f_globals.get('__name__', '?')
+        except AttributeError: # IronPython _getframe only exists with FullFrames
+            callermodule = '?'
         func.__module__ = getattr(self, 'module', callermodule)
         func.__dict__.update(kw)
 
diff --git a/IPython/lib/inputhook.py b/IPython/lib/inputhook.py
index 44cebbb..a29cec0 100644
--- a/IPython/lib/inputhook.py
+++ b/IPython/lib/inputhook.py
@@ -18,6 +18,8 @@ try:
     import ctypes
 except ImportError:
     ctypes = None
+except SystemError: # IronPython issue, 2/8/2014
+    ctypes = None
 import os
 import sys
 from distutils.version import LooseVersion as V
diff --git a/IPython/utils/_process_cli.py b/IPython/utils/_process_cli.py
new file mode 100644
index 0000000..eb69d3f
--- /dev/null
+++ b/IPython/utils/_process_cli.py
@@ -0,0 +1,63 @@
+"""cli-specific implementation of process utilities.
+
+cli - Common Language Infrastructure for IronPython. Code
+      can run on any operating system. Check os.name for os-
+      specific settings.
+
+This file is only meant to be imported by process.py, not by end-users.
+
+This file is largely untested. To become a full drop-in process
+interface for IronPython will probably require you to help fill
+in the details. 
+"""
+
+# Import cli libraries:
+import clr
+import System
+
+# Import Python libraries:
+import os
+
+# Import IPython libraries:
+from IPython.utils import py3compat
+from ._process_common import arg_split
+
+def _find_cmd(cmd):
+    """Find the full path to a command using which."""
+    paths = System.Environment.GetEnvironmentVariable("PATH").Split(os.pathsep)
+    for path in paths:
+        filename = os.path.join(path, cmd)
+        if System.IO.File.Exists(filename):
+            return py3compat.bytes_to_str(filename)
+    raise OSError("command %r not found" % cmd)
+
+def system(cmd):
+    """
+    system(cmd) should work in a cli environment on Mac OSX, Linux,
+    and Windows
+    """
+    psi = System.Diagnostics.ProcessStartInfo(cmd)
+    psi.RedirectStandardOutput = True
+    psi.RedirectStandardError = True
+    psi.WindowStyle = System.Diagnostics.ProcessWindowStyle.Normal
+    psi.UseShellExecute = False
+    # Start up process:
+    reg = System.Diagnostics.Process.Start(psi)
+
+def getoutput(cmd):
+    """
+    getoutput(cmd) should work in a cli environment on Mac OSX, Linux,
+    and Windows
+    """
+    psi = System.Diagnostics.ProcessStartInfo(cmd)
+    psi.RedirectStandardOutput = True
+    psi.RedirectStandardError = True
+    psi.WindowStyle = System.Diagnostics.ProcessWindowStyle.Normal
+    psi.UseShellExecute = False
+    # Start up process:
+    reg = System.Diagnostics.Process.Start(psi)
+    myOutput = reg.StandardOutput
+    output = myOutput.ReadToEnd()
+    myError = reg.StandardError
+    error = myError.ReadToEnd()
+    return output
diff --git a/IPython/utils/io.py b/IPython/utils/io.py
index 1932949..c3390ed 100644
--- a/IPython/utils/io.py
+++ b/IPython/utils/io.py
@@ -81,7 +81,7 @@ class IOStream:
         pass
 
 # setup stdin/stdout/stderr to sys.stdin/sys.stdout/sys.stderr
-devnull = open(os.devnull, 'a')
+devnull = open(os.devnull, 'w') 
 stdin = IOStream(sys.stdin, fallback=devnull)
 stdout = IOStream(sys.stdout, fallback=devnull)
 stderr = IOStream(sys.stderr, fallback=devnull)
diff --git a/IPython/utils/process.py b/IPython/utils/process.py
index 826aa51..2e8d0f9 100644
--- a/IPython/utils/process.py
+++ b/IPython/utils/process.py
@@ -22,11 +22,12 @@ import shlex
 
 # Our own
 if sys.platform == 'win32':
-    from ._process_win32 import _find_cmd, system, getoutput, AvoidUNCPath, arg_split
+    from ._process_win32 import _find_cmd, system, getoutput, arg_split
+elif sys.platform == 'cli':
+    from ._process_cli import _find_cmd, system, getoutput, arg_split
 else:
     from ._process_posix import _find_cmd, system, getoutput, arg_split
 
-
 from ._process_common import getoutputerror, get_output_error_code, process_handler
 from . import py3compat