diff -r ab7f57e92629 Doc/library/os.rst
--- a/Doc/library/os.rst	Mon Apr 14 12:16:18 2014 -0400
+++ b/Doc/library/os.rst	Tue Apr 15 16:51:45 2014 -0400
@@ -2732,8 +2732,21 @@
 
 .. function:: popen(...)
 
-   Run child processes, returning opened pipes for communications.  These functions
-   are described in section :ref:`os-newstreams`.
+   Open a pipe to or from *command*.  The return value is an open file object
+   connected to the pipe, which can be read or written depending on whether *mode*
+   is ``'r'`` (default) or ``'w'``. The *buffering* argument has the same meaning as
+   the corresponding argument to the built-in :func:`open` function. The
+   returned file object reads or writes text strings rather than bytes.
+
+   The ``close`` method returns None, if the subprocess exited successfully, or
+   the subprocess's return code. On POSIX systems, this contains either the
+   positive return code left-shifted by one byte or the signal number that
+   terminated the process, negated. On Windows systems, this contains the
+   signed integer return code from the child process.
+
+   This is implemented using :class:`subprocess.Popen`; see that class's
+   documentation for more powerful ways to manage and communicate with
+   subprocesses.
 
 
 .. function:: spawnl(mode, path, ...)