diff --git a/IPython/kernel/core/fd_redirector.py b/IPython/kernel/core/fd_redirector.py
index 0941fac..510a439 100644
--- a/IPython/kernel/core/fd_redirector.py
+++ b/IPython/kernel/core/fd_redirector.py
@@ -2,6 +2,8 @@
 
 """
 Stdout/stderr redirector, at the OS level, using file descriptors.
+
+This also works under windows.
 """
 
 __docformat__ = "restructuredtext en"
@@ -31,8 +33,12 @@ class FDRedirector(object):
         """
         self.fd = fd
         self.started = False
+        self.piper = None
+        self.pipew = None
 
     def start(self):
+        """ Setup the redirection.
+        """
         if not self.started:
             self.oldhandle = os.dup(self.fd)
             self.piper, self.pipew = os.pipe()
@@ -42,12 +48,17 @@ class FDRedirector(object):
             self.started = True
 
     def flush(self):
+        """ Flush the captured output, similar to the flush method of any
+        stream.
+        """
         if self.fd == STDOUT:
             sys.stdout.flush()
         elif self.fd == STDERR:
             sys.stderr.flush()
 
     def stop(self):
+        """ Unset the redirection and return the captured output. 
+        """
         if self.started:
             self.flush()
             os.dup2(self.oldhandle, self.fd)
@@ -62,6 +73,9 @@ class FDRedirector(object):
             return ''
 
     def getvalue(self):
+        """ Return the output captured since the last getvalue, or the
+        start of the redirection.
+        """
         output = self.stop()
         self.start()
         return output
diff --git a/IPython/kernel/core/file_like.py b/IPython/kernel/core/file_like.py
index a09f47a..f984451 100644
--- a/IPython/kernel/core/file_like.py
+++ b/IPython/kernel/core/file_like.py
@@ -25,25 +25,42 @@ class FileLike(object):
         self.write = write_callback
 
     def flush(self):
+        """ This method is there for compatibility with other file-like
+        objects.
+        """
         pass
 
     def close(self):
+        """ This method is there for compatibility with other file-like
+        objects.
+        """
         pass
 
     def writelines(self, lines):
-        for line in lines:
-            self.write(line)
+        map(self.write, lines)
 
     def isatty(self):
+        """ This method is there for compatibility with other file-like
+        objects.
+        """
         return False
 
     def getvalue(self):
+        """ This method is there for compatibility with other file-like
+        objects.
+        """
         return ''
 
     def reset(self):
+        """ This method is there for compatibility with other file-like
+        objects.
+        """
         pass
 
     def truncate(self):
+        """ This method is there for compatibility with other file-like
+        objects.
+        """
         pass
 
 
diff --git a/IPython/kernel/core/redirector_output_trap.py b/IPython/kernel/core/redirector_output_trap.py
index fb396ce..fcc3f71 100644
--- a/IPython/kernel/core/redirector_output_trap.py
+++ b/IPython/kernel/core/redirector_output_trap.py
@@ -31,6 +31,10 @@ class RedirectorOutputTrap(OutputTrap):
     # OutputTrap interface.
     #------------------------------------------------------------------------
     def __init__(self, out_callback, err_callback):
+        """ 
+        out_callback : callable called when there is output in the stdout
+        err_callback : callable called when there is output in the stderr
+        """
         # Callback invoked on write to stdout and stderr 
         self.out_callback = out_callback
         self.err_callback = err_callback
diff --git a/IPython/kernel/core/sync_traceback_trap.py b/IPython/kernel/core/sync_traceback_trap.py
index df9b0e5..cf9e1bf 100644
--- a/IPython/kernel/core/sync_traceback_trap.py
+++ b/IPython/kernel/core/sync_traceback_trap.py
@@ -21,9 +21,17 @@ from traceback_trap import TracebackTrap
 from IPython.ultraTB import ColorTB
 
 class SyncTracebackTrap(TracebackTrap):
+    """ TracebackTrap that displays immediatly the traceback in addition
+    to capturing it. Useful in frontends, as without this traceback trap, 
+    some tracebacks never get displayed.
+    """
 
     def __init__(self, sync_formatter=None, formatters=None,
                                                     raiseException=True):
+        """
+        sync_formatter: Callable to display the traceback.
+        formatters: A list of formatters to apply.
+        """
         TracebackTrap.__init__(self, formatters=formatters)
         if sync_formatter is None:
             sync_formatter = ColorTB(color_scheme='LightBG')