Issue #24225: Within idlelib files, update idlelib module names.
This follows the previous patch that changed idlelib file names.
Class names that matched old module names are not changed.
Change idlelib imports in turtledemo.__main__.

Exception: config-extensions.def.  Previously, extension section
names, file names, and class names had to match.  Changing section
names would create cross-version conflicts in config-extensions.cfg
(user customizations).  Instead map old names to new file names
at point of import in editor.EditorWindow.load_extension.

Patch extensively tested with test_idle, idle_test.htest.py, a custom
import-all test, running IDLE in a console to catch messages,
and testing each menu item.  Based on a patch by Al Sweigart.
diff --git a/Lib/idlelib/__main__.py b/Lib/idlelib/__main__.py
index 2edf5f7..6349ec7 100644
--- a/Lib/idlelib/__main__.py
+++ b/Lib/idlelib/__main__.py
@@ -3,6 +3,6 @@
 
 Run IDLE as python -m idlelib
 """
-import idlelib.PyShell
-idlelib.PyShell.main()
+import idlelib.pyshell
+idlelib.pyshell.main()
 # This file does not work for 2.7; See issue 24212.
diff --git a/Lib/idlelib/autocomplete.py b/Lib/idlelib/autocomplete.py
index b9ec539..6e75f67 100644
--- a/Lib/idlelib/autocomplete.py
+++ b/Lib/idlelib/autocomplete.py
@@ -1,4 +1,4 @@
-"""AutoComplete.py - An IDLE extension for automatically completing names.
+"""autocomplete.py - An IDLE extension for automatically completing names.
 
 This extension can complete either attribute names of file names. It can pop
 a window with all available names, for the user to select from.
@@ -7,7 +7,7 @@
 import sys
 import string
 
-from idlelib.configHandler import idleConf
+from idlelib.config import idleConf
 
 # This string includes all chars that may be in an identifier
 ID_CHARS = string.ascii_letters + string.digits + "_"
@@ -15,8 +15,8 @@
 # These constants represent the two different types of completions
 COMPLETE_ATTRIBUTES, COMPLETE_FILES = range(1, 2+1)
 
-from idlelib import AutoCompleteWindow
-from idlelib.HyperParser import HyperParser
+from idlelib import autocomplete_w
+from idlelib.hyperparser import HyperParser
 
 import __main__
 
@@ -49,7 +49,7 @@
         self._delayed_completion_index = None
 
     def _make_autocomplete_window(self):
-        return AutoCompleteWindow.AutoCompleteWindow(self.text)
+        return autocomplete_w.AutoCompleteWindow(self.text)
 
     def _remove_autocomplete_window(self, event=None):
         if self.autocompletewindow:
diff --git a/Lib/idlelib/autocomplete_w.py b/Lib/idlelib/autocomplete_w.py
index 2ee6878..c66b3df 100644
--- a/Lib/idlelib/autocomplete_w.py
+++ b/Lib/idlelib/autocomplete_w.py
@@ -1,9 +1,9 @@
 """
-An auto-completion window for IDLE, used by the AutoComplete extension
+An auto-completion window for IDLE, used by the autocomplete extension
 """
 from tkinter import *
-from idlelib.MultiCall import MC_SHIFT
-from idlelib.AutoComplete import COMPLETE_FILES, COMPLETE_ATTRIBUTES
+from idlelib.multicall import MC_SHIFT
+from idlelib.autocomplete import COMPLETE_FILES, COMPLETE_ATTRIBUTES
 
 HIDE_VIRTUAL_EVENT_NAME = "<<autocompletewindow-hide>>"
 HIDE_SEQUENCES = ("<FocusOut>", "<ButtonPress>")
@@ -34,8 +34,8 @@
         self.completions = None
         # A list with more completions, or None
         self.morecompletions = None
-        # The completion mode. Either AutoComplete.COMPLETE_ATTRIBUTES or
-        # AutoComplete.COMPLETE_FILES
+        # The completion mode. Either autocomplete.COMPLETE_ATTRIBUTES or
+        # autocomplete.COMPLETE_FILES
         self.mode = None
         # The current completion start, on the text box (a string)
         self.start = None
diff --git a/Lib/idlelib/browser.py b/Lib/idlelib/browser.py
index d09c52f..9968333 100644
--- a/Lib/idlelib/browser.py
+++ b/Lib/idlelib/browser.py
@@ -14,13 +14,13 @@
 import sys
 import pyclbr
 
-from idlelib import PyShell
-from idlelib.WindowList import ListedToplevel
-from idlelib.TreeWidget import TreeNode, TreeItem, ScrolledCanvas
-from idlelib.configHandler import idleConf
+from idlelib import pyshell
+from idlelib.windows import ListedToplevel
+from idlelib.tree import TreeNode, TreeItem, ScrolledCanvas
+from idlelib.config import idleConf
 
 file_open = None  # Method...Item and Class...Item use this.
-# Normally PyShell.flist.open, but there is no PyShell.flist for htest.
+# Normally pyshell.flist.open, but there is no pyshell.flist for htest.
 
 class ClassBrowser:
 
@@ -32,7 +32,7 @@
         """
         global file_open
         if not _htest:
-            file_open = PyShell.flist.open
+            file_open = pyshell.flist.open
         self.name = name
         self.file = os.path.join(path[0], self.name + ".py")
         self._htest = _htest
@@ -95,7 +95,7 @@
             return
         if not os.path.exists(self.file):
             return
-        PyShell.flist.open(self.file)
+        pyshell.flist.open(self.file)
 
     def IsExpandable(self):
         return os.path.normcase(self.file[-3:]) == ".py"
@@ -226,7 +226,7 @@
             file = sys.argv[0]
     dir, file = os.path.split(file)
     name = os.path.splitext(file)[0]
-    flist = PyShell.PyShellFileList(parent)
+    flist = pyshell.PyShellFileList(parent)
     global file_open
     file_open = flist.open
     ClassBrowser(flist, name, [dir], _htest=True)
diff --git a/Lib/idlelib/calltip_w.py b/Lib/idlelib/calltip_w.py
index 8e68a76..9f6cdc1 100644
--- a/Lib/idlelib/calltip_w.py
+++ b/Lib/idlelib/calltip_w.py
@@ -1,7 +1,7 @@
 """A CallTip window class for Tkinter/IDLE.
 
-After ToolTip.py, which uses ideas gleaned from PySol
-Used by the CallTips IDLE extension.
+After tooltip.py, which uses ideas gleaned from PySol
+Used by the calltips IDLE extension.
 """
 from tkinter import Toplevel, Label, LEFT, SOLID, TclError
 
diff --git a/Lib/idlelib/calltips.py b/Lib/idlelib/calltips.py
index 81bd5f1..3a9b1c6 100644
--- a/Lib/idlelib/calltips.py
+++ b/Lib/idlelib/calltips.py
@@ -1,4 +1,4 @@
-"""CallTips.py - An IDLE Extension to Jog Your Memory
+"""calltips.py - An IDLE Extension to Jog Your Memory
 
 Call Tips are floating windows which display function, class, and method
 parameter and docstring information when you type an opening parenthesis, and
@@ -12,8 +12,8 @@
 import textwrap
 import types
 
-from idlelib import CallTipWindow
-from idlelib.HyperParser import HyperParser
+from idlelib import calltip_w
+from idlelib.hyperparser import HyperParser
 
 class CallTips:
 
@@ -37,7 +37,7 @@
 
     def _make_tk_calltip_window(self):
         # See __init__ for usage
-        return CallTipWindow.CallTip(self.text)
+        return calltip_w.CallTip(self.text)
 
     def _remove_calltip_window(self, event=None):
         if self.active_calltip:
diff --git a/Lib/idlelib/codecontext.py b/Lib/idlelib/codecontext.py
index 7d25ada..2a21a1f 100644
--- a/Lib/idlelib/codecontext.py
+++ b/Lib/idlelib/codecontext.py
@@ -1,11 +1,11 @@
-"""CodeContext - Extension to display the block context above the edit window
+"""codecontext - Extension to display the block context above the edit window
 
 Once code has scrolled off the top of a window, it can be difficult to
 determine which block you are in.  This extension implements a pane at the top
 of each IDLE edit window which provides block structure hints.  These hints are
 the lines which contain the block opening keywords, e.g. 'if', for the
 enclosing block.  The number of hint lines is determined by the numlines
-variable in the CodeContext section of config-extensions.def. Lines which do
+variable in the codecontext section of config-extensions.def. Lines which do
 not open blocks are not shown in the context hints pane.
 
 """
@@ -13,7 +13,7 @@
 from tkinter.constants import TOP, LEFT, X, W, SUNKEN
 import re
 from sys import maxsize as INFINITY
-from idlelib.configHandler import idleConf
+from idlelib.config import idleConf
 
 BLOCKOPENERS = {"class", "def", "elif", "else", "except", "finally", "for",
                     "if", "try", "while", "with"}
diff --git a/Lib/idlelib/colorizer.py b/Lib/idlelib/colorizer.py
index 9f31349..ca365f7 100644
--- a/Lib/idlelib/colorizer.py
+++ b/Lib/idlelib/colorizer.py
@@ -2,8 +2,8 @@
 import re
 import keyword
 import builtins
-from idlelib.Delegator import Delegator
-from idlelib.configHandler import idleConf
+from idlelib.delegator import Delegator
+from idlelib.config import idleConf
 
 DEBUG = False
 
@@ -235,7 +235,7 @@
 
 def _color_delegator(parent):  # htest #
     from tkinter import Toplevel, Text
-    from idlelib.Percolator import Percolator
+    from idlelib.percolator import Percolator
 
     top = Toplevel(parent)
     top.title("Test ColorDelegator")
diff --git a/Lib/idlelib/config.py b/Lib/idlelib/config.py
index 8ac1f60..b9e1c6d 100644
--- a/Lib/idlelib/config.py
+++ b/Lib/idlelib/config.py
@@ -7,7 +7,7 @@
 and if a file becomes empty, it will be deleted.
 
 The contents of the user files may be altered using the Options/Configure IDLE
-menu to access the configuration GUI (configDialog.py), or manually.
+menu to access the configuration GUI (configdialog.py), or manually.
 
 Throughout this module there is an emphasis on returning useable defaults
 when a problem occurs in returning a requested configuration value back to
@@ -230,7 +230,7 @@
                 return self.userCfg[configType].Get(section, option,
                                                     type=type, raw=raw)
         except ValueError:
-            warning = ('\n Warning: configHandler.py - IdleConf.GetOption -\n'
+            warning = ('\n Warning: config.py - IdleConf.GetOption -\n'
                        ' invalid %r value for configuration option %r\n'
                        ' from section %r: %r' %
                        (type, option, section,
@@ -247,7 +247,7 @@
             pass
         #returning default, print warning
         if warn_on_default:
-            warning = ('\n Warning: configHandler.py - IdleConf.GetOption -\n'
+            warning = ('\n Warning: config.py - IdleConf.GetOption -\n'
                        ' problem retrieving configuration option %r\n'
                        ' from section %r.\n'
                        ' returning default value: %r' %
@@ -358,7 +358,7 @@
         for element in theme:
             if not cfgParser.has_option(themeName, element):
                 # Print warning that will return a default color
-                warning = ('\n Warning: configHandler.IdleConf.GetThemeDict'
+                warning = ('\n Warning: config.IdleConf.GetThemeDict'
                            ' -\n problem retrieving theme element %r'
                            '\n from theme %r.\n'
                            ' returning default color: %r' %
@@ -644,7 +644,7 @@
                 if binding:
                     keyBindings[event] = binding
                 else: #we are going to return a default, print warning
-                    warning=('\n Warning: configHandler.py - IdleConf.GetCoreKeys'
+                    warning=('\n Warning: config.py - IdleConf.GetCoreKeys'
                                ' -\n problem retrieving key binding for event %r'
                                '\n from key set %r.\n'
                                ' returning default value: %r' %
diff --git a/Lib/idlelib/config_sec.py b/Lib/idlelib/config_sec.py
index 5137836..7b59124 100644
--- a/Lib/idlelib/config_sec.py
+++ b/Lib/idlelib/config_sec.py
@@ -1,7 +1,7 @@
 """
 Dialog that allows user to specify a new config file section name.
 Used to get new highlight theme and keybinding set names.
-The 'return value' for the dialog, used two placed in configDialog.py,
+The 'return value' for the dialog, used two placed in configdialog.py,
 is the .result attribute set in the Ok and Cancel methods.
 """
 from tkinter import *
diff --git a/Lib/idlelib/configdialog.py b/Lib/idlelib/configdialog.py
index b702253..b58806e 100644
--- a/Lib/idlelib/configdialog.py
+++ b/Lib/idlelib/configdialog.py
@@ -14,14 +14,14 @@
 import tkinter.colorchooser as tkColorChooser
 import tkinter.font as tkFont
 
-from idlelib.configHandler import idleConf
-from idlelib.dynOptionMenuWidget import DynOptionMenu
-from idlelib.keybindingDialog import GetKeysDialog
-from idlelib.configSectionNameDialog import GetCfgSectionNameDialog
-from idlelib.configHelpSourceEdit import GetHelpSourceDialog
+from idlelib.config import idleConf
+from idlelib.dynoption import DynOptionMenu
+from idlelib.config_key import GetKeysDialog
+from idlelib.config_sec import GetCfgSectionNameDialog
+from idlelib.config_help import GetHelpSourceDialog
 from idlelib.tabbedpages import TabbedPageSet
-from idlelib.textView import view_text
-from idlelib import macosxSupport
+from idlelib.textview import view_text
+from idlelib import macosx
 
 class ConfigDialog(Toplevel):
 
@@ -91,7 +91,7 @@
         self.create_action_buttons().pack(side=BOTTOM)
 
     def create_action_buttons(self):
-        if macosxSupport.isAquaTk():
+        if macosx.isAquaTk():
             # Changing the default padding on OSX results in unreadable
             # text in the buttons
             paddingArgs = {}
diff --git a/Lib/idlelib/debugger.py b/Lib/idlelib/debugger.py
index d5e217d..9af626c 100644
--- a/Lib/idlelib/debugger.py
+++ b/Lib/idlelib/debugger.py
@@ -1,9 +1,9 @@
 import os
 import bdb
 from tkinter import *
-from idlelib.WindowList import ListedToplevel
-from idlelib.ScrolledList import ScrolledList
-from idlelib import macosxSupport
+from idlelib.windows import ListedToplevel
+from idlelib.scrolledlist import ScrolledList
+from idlelib import macosx
 
 
 class Idb(bdb.Bdb):
@@ -34,8 +34,10 @@
             return True
         else:
             prev_frame = frame.f_back
-            if prev_frame.f_code.co_filename.count('Debugger.py'):
-                # (that test will catch both Debugger.py and RemoteDebugger.py)
+            prev_name = prev_frame.f_code.co_filename
+            if 'idlelib' in prev_name and 'debugger' in prev_name:
+                # catch both idlelib/debugger.py and idlelib/debugger_r.py
+                # on both posix and windows
                 return False
             return self.in_rpc_code(prev_frame)
 
@@ -370,7 +372,7 @@
 class StackViewer(ScrolledList):
 
     def __init__(self, master, flist, gui):
-        if macosxSupport.isAquaTk():
+        if macosx.isAquaTk():
             # At least on with the stock AquaTk version on OSX 10.4 you'll
             # get a shaking GUI that eventually kills IDLE if the width
             # argument is specified.
@@ -502,7 +504,7 @@
             #
             # There is also an obscure bug in sorted(dict) where the
             # interpreter gets into a loop requesting non-existing dict[0],
-            # dict[1], dict[2], etc from the RemoteDebugger.DictProxy.
+            # dict[1], dict[2], etc from the debugger_r.DictProxy.
             ###
             keys_list = dict.keys()
             names = sorted(keys_list)
diff --git a/Lib/idlelib/debugger_r.py b/Lib/idlelib/debugger_r.py
index be2262f..bc97127 100644
--- a/Lib/idlelib/debugger_r.py
+++ b/Lib/idlelib/debugger_r.py
@@ -21,7 +21,7 @@
 """
 
 import types
-from idlelib import Debugger
+from idlelib import debugger
 
 debugging = 0
 
@@ -187,7 +187,7 @@
 
     """
     gui_proxy = GUIProxy(rpchandler, gui_adap_oid)
-    idb = Debugger.Idb(gui_proxy)
+    idb = debugger.Idb(gui_proxy)
     idb_adap = IdbAdapter(idb)
     rpchandler.register(idb_adap_oid, idb_adap)
     return idb_adap_oid
@@ -362,7 +362,7 @@
     idb_adap_oid = rpcclt.remotecall("exec", "start_the_debugger",\
                                    (gui_adap_oid,), {})
     idb_proxy = IdbProxy(rpcclt, pyshell, idb_adap_oid)
-    gui = Debugger.Debugger(pyshell, idb_proxy)
+    gui = debugger.Debugger(pyshell, idb_proxy)
     gui_adap = GUIAdapter(rpcclt, gui)
     rpcclt.register(gui_adap_oid, gui_adap)
     return gui
@@ -373,7 +373,7 @@
     Request that the RPCServer shut down the subprocess debugger and link.
     Unregister the GUIAdapter, which will cause a GC on the Idle process
     debugger and RPC link objects.  (The second reference to the debugger GUI
-    is deleted in PyShell.close_remote_debugger().)
+    is deleted in pyshell.close_remote_debugger().)
 
     """
     close_subprocess_debugger(rpcclt)
diff --git a/Lib/idlelib/debugobj.py b/Lib/idlelib/debugobj.py
index 7b57aa4..4016c03 100644
--- a/Lib/idlelib/debugobj.py
+++ b/Lib/idlelib/debugobj.py
@@ -11,7 +11,7 @@
 
 import re
 
-from idlelib.TreeWidget import TreeItem, TreeNode, ScrolledCanvas
+from idlelib.tree import TreeItem, TreeNode, ScrolledCanvas
 
 from reprlib import Repr
 
@@ -126,7 +126,7 @@
     import sys
     from tkinter import Tk
     root = Tk()
-    root.title("Test ObjectBrowser")
+    root.title("Test debug object browser")
     width, height, x, y = list(map(int, re.split('[x+]', parent.geometry())))
     root.geometry("+%d+%d"%(x, y + 150))
     root.configure(bd=0, bg="yellow")
diff --git a/Lib/idlelib/editor.py b/Lib/idlelib/editor.py
index b5868be..3aa5278 100644
--- a/Lib/idlelib/editor.py
+++ b/Lib/idlelib/editor.py
@@ -12,15 +12,15 @@
 import traceback
 import webbrowser
 
-from idlelib.MultiCall import MultiCallCreator
-from idlelib import WindowList
-from idlelib import SearchDialog
-from idlelib import GrepDialog
-from idlelib import ReplaceDialog
-from idlelib import PyParse
-from idlelib.configHandler import idleConf
-from idlelib import aboutDialog, textView, configDialog
-from idlelib import macosxSupport
+from idlelib.multicall import MultiCallCreator
+from idlelib import windows
+from idlelib import search
+from idlelib import grep
+from idlelib import replace
+from idlelib import pyparse
+from idlelib.config import idleConf
+from idlelib import help_about, textview, configdialog
+from idlelib import macosx
 from idlelib import help
 
 # The default tab setting for a Text widget, in average-width characters.
@@ -67,7 +67,7 @@
     def show_dialog(self, parent):
         self.parent = parent
         fn=os.path.join(os.path.abspath(os.path.dirname(__file__)),'help.txt')
-        self.dlg = dlg = textView.view_file(parent,'Help',fn, modal=False)
+        self.dlg = dlg = textview.view_file(parent,'Help',fn, modal=False)
         dlg.bind('<Destroy>', self.destroy, '+')
 
     def nearwindow(self, near):
@@ -89,13 +89,13 @@
 
 
 class EditorWindow(object):
-    from idlelib.Percolator import Percolator
-    from idlelib.ColorDelegator import ColorDelegator
-    from idlelib.UndoDelegator import UndoDelegator
-    from idlelib.IOBinding import IOBinding, filesystemencoding, encoding
-    from idlelib import Bindings
+    from idlelib.percolator import Percolator
+    from idlelib.colorizer import ColorDelegator
+    from idlelib.undo import UndoDelegator
+    from idlelib.iomenu import IOBinding, filesystemencoding, encoding
+    from idlelib import mainmenu
     from tkinter import Toplevel
-    from idlelib.MultiStatusBar import MultiStatusBar
+    from idlelib.statusbar import MultiStatusBar
 
     help_url = None
 
@@ -136,11 +136,11 @@
         except AttributeError:
             sys.ps1 = '>>> '
         self.menubar = Menu(root)
-        self.top = top = WindowList.ListedToplevel(root, menu=self.menubar)
+        self.top = top = windows.ListedToplevel(root, menu=self.menubar)
         if flist:
             self.tkinter_vars = flist.vars
             #self.top.instance_dict makes flist.inversedict available to
-            #configDialog.py so it can access all EditorWindow instances
+            #configdialog.py so it can access all EditorWindow instances
             self.top.instance_dict = flist.inversedict
         else:
             self.tkinter_vars = {}  # keys: Tkinter event names
@@ -173,7 +173,7 @@
 
         self.top.protocol("WM_DELETE_WINDOW", self.close)
         self.top.bind("<<close-window>>", self.close_event)
-        if macosxSupport.isAquaTk():
+        if macosx.isAquaTk():
             # Command-W on editorwindows doesn't work without this.
             text.bind('<<close-window>>', self.close_event)
             # Some OS X systems have only one mouse button, so use
@@ -309,7 +309,7 @@
                 menu.add_separator()
                 end = end + 1
             self.wmenu_end = end
-            WindowList.register_callback(self.postwindowsmenu)
+            windows.register_callback(self.postwindowsmenu)
 
         # Some abstractions so IDLE extensions are cross-IDE
         self.askyesno = tkMessageBox.askyesno
@@ -418,7 +418,7 @@
             underline, label = prepstr(label)
             menudict[name] = menu = Menu(mbar, name=name, tearoff=0)
             mbar.add_cascade(label=label, menu=menu, underline=underline)
-        if macosxSupport.isCarbonTk():
+        if macosx.isCarbonTk():
             # Insert the application menu
             menudict['application'] = menu = Menu(mbar, name='apple',
                                                   tearoff=0)
@@ -439,7 +439,7 @@
             end = -1
         if end > self.wmenu_end:
             menu.delete(self.wmenu_end+1, end)
-        WindowList.add_windows_to_menu(menu)
+        windows.add_windows_to_menu(menu)
 
     rmenu = None
 
@@ -507,17 +507,17 @@
 
     def about_dialog(self, event=None):
         "Handle Help 'About IDLE' event."
-        # Synchronize with macosxSupport.overrideRootMenu.about_dialog.
-        aboutDialog.AboutDialog(self.top,'About IDLE')
+        # Synchronize with macosx.overrideRootMenu.about_dialog.
+        help_about.AboutDialog(self.top,'About IDLE')
 
     def config_dialog(self, event=None):
         "Handle Options 'Configure IDLE' event."
-        # Synchronize with macosxSupport.overrideRootMenu.config_dialog.
-        configDialog.ConfigDialog(self.top,'Settings')
+        # Synchronize with macosx.overrideRootMenu.config_dialog.
+        configdialog.ConfigDialog(self.top,'Settings')
 
     def help_dialog(self, event=None):
         "Handle Help 'IDLE Help' event."
-        # Synchronize with macosxSupport.overrideRootMenu.help_dialog.
+        # Synchronize with macosx.overrideRootMenu.help_dialog.
         if self.root:
             parent = self.root
         else:
@@ -590,23 +590,23 @@
         return "break"
 
     def find_event(self, event):
-        SearchDialog.find(self.text)
+        search.find(self.text)
         return "break"
 
     def find_again_event(self, event):
-        SearchDialog.find_again(self.text)
+        search.find_again(self.text)
         return "break"
 
     def find_selection_event(self, event):
-        SearchDialog.find_selection(self.text)
+        search.find_selection(self.text)
         return "break"
 
     def find_in_files_event(self, event):
-        GrepDialog.grep(self.text, self.io, self.flist)
+        grep.grep(self.text, self.io, self.flist)
         return "break"
 
     def replace_event(self, event):
-        ReplaceDialog.replace(self.text)
+        replace.replace(self.text)
         return "break"
 
     def goto_line_event(self, event):
@@ -673,12 +673,12 @@
                 return
         head, tail = os.path.split(filename)
         base, ext = os.path.splitext(tail)
-        from idlelib import ClassBrowser
-        ClassBrowser.ClassBrowser(self.flist, base, [head])
+        from idlelib import browser
+        browser.ClassBrowser(self.flist, base, [head])
 
     def open_path_browser(self, event=None):
-        from idlelib import PathBrowser
-        PathBrowser.PathBrowser(self.flist)
+        from idlelib import pathbrowser
+        pathbrowser.PathBrowser(self.flist)
 
     def open_turtle_demo(self, event = None):
         import subprocess
@@ -739,7 +739,7 @@
 
     def ResetColorizer(self):
         "Update the color theme"
-        # Called from self.filename_change_hook and from configDialog.py
+        # Called from self.filename_change_hook and from configdialog.py
         self._rmcolorizer()
         self._addcolorizer()
         theme = idleConf.CurrentTheme()
@@ -772,14 +772,14 @@
 
     def ResetFont(self):
         "Update the text widgets' font if it is changed"
-        # Called from configDialog.py
+        # Called from configdialog.py
 
         self.text['font'] = idleConf.GetFont(self.root, 'main','EditorWindow')
 
     def RemoveKeybindings(self):
         "Remove the keybindings before they are changed."
-        # Called from configDialog.py
-        self.Bindings.default_keydefs = keydefs = idleConf.GetCurrentKeySet()
+        # Called from configdialog.py
+        self.mainmenu.default_keydefs = keydefs = idleConf.GetCurrentKeySet()
         for event, keylist in keydefs.items():
             self.text.event_delete(event, *keylist)
         for extensionName in self.get_standard_extension_names():
@@ -790,8 +790,8 @@
 
     def ApplyKeybindings(self):
         "Update the keybindings after they are changed"
-        # Called from configDialog.py
-        self.Bindings.default_keydefs = keydefs = idleConf.GetCurrentKeySet()
+        # Called from configdialog.py
+        self.mainmenu.default_keydefs = keydefs = idleConf.GetCurrentKeySet()
         self.apply_bindings()
         for extensionName in self.get_standard_extension_names():
             xkeydefs = idleConf.GetExtensionBindings(extensionName)
@@ -799,7 +799,7 @@
                 self.apply_bindings(xkeydefs)
         #update menu accelerators
         menuEventDict = {}
-        for menu in self.Bindings.menudefs:
+        for menu in self.mainmenu.menudefs:
             menuEventDict[menu[0]] = {}
             for item in menu[1]:
                 if item:
@@ -826,7 +826,7 @@
 
     def set_notabs_indentwidth(self):
         "Update the indentwidth if changed and not using tabs in this window"
-        # Called from configDialog.py
+        # Called from configdialog.py
         if not self.usetabs:
             self.indentwidth = idleConf.GetOption('main', 'Indent','num-spaces',
                                                   type='int')
@@ -1006,7 +1006,7 @@
     def _close(self):
         if self.io.filename:
             self.update_recent_files_list(new_file=self.io.filename)
-        WindowList.unregister_callback(self.postwindowsmenu)
+        windows.unregister_callback(self.postwindowsmenu)
         self.unload_extensions()
         self.io.close()
         self.io = None
@@ -1044,12 +1044,25 @@
     def get_standard_extension_names(self):
         return idleConf.GetExtensions(editor_only=True)
 
+    extfiles = {  # map config-extension section names to new file names
+        'AutoComplete': 'autocomplete',
+        'AutoExpand': 'autoexpand',
+        'CallTips': 'calltips',
+        'CodeContext': 'codecontext',
+        'FormatParagraph': 'paragraph',
+        'ParenMatch': 'parenmatch',
+        'RstripExtension': 'rstrip',
+        'ScriptBinding': 'runscript',
+        'ZoomHeight': 'zoomheight',
+        }
+
     def load_extension(self, name):
+        fname = self.extfiles.get(name, name)
         try:
             try:
-                mod = importlib.import_module('.' + name, package=__package__)
+                mod = importlib.import_module('.' + fname, package=__package__)
             except (ImportError, TypeError):
-                mod = importlib.import_module(name)
+                mod = importlib.import_module(fname)
         except ImportError:
             print("\nFailed to import extension: ", name)
             raise
@@ -1073,7 +1086,7 @@
 
     def apply_bindings(self, keydefs=None):
         if keydefs is None:
-            keydefs = self.Bindings.default_keydefs
+            keydefs = self.mainmenu.default_keydefs
         text = self.text
         text.keydefs = keydefs
         for event, keylist in keydefs.items():
@@ -1086,9 +1099,9 @@
         Menus that are absent or None in self.menudict are ignored.
         """
         if menudefs is None:
-            menudefs = self.Bindings.menudefs
+            menudefs = self.mainmenu.menudefs
         if keydefs is None:
-            keydefs = self.Bindings.default_keydefs
+            keydefs = self.mainmenu.default_keydefs
         menudict = self.menudict
         text = self.text
         for mname, entrylist in menudefs:
@@ -1315,7 +1328,7 @@
             # adjust indentation for continuations and block
             # open/close first need to find the last stmt
             lno = index2line(text.index('insert'))
-            y = PyParse.Parser(self.indentwidth, self.tabwidth)
+            y = pyparse.Parser(self.indentwidth, self.tabwidth)
             if not self.context_use_ps1:
                 for context in self.num_context_lines:
                     startat = max(lno - context, 1)
@@ -1339,22 +1352,22 @@
                 y.set_lo(0)
 
             c = y.get_continuation_type()
-            if c != PyParse.C_NONE:
+            if c != pyparse.C_NONE:
                 # The current stmt hasn't ended yet.
-                if c == PyParse.C_STRING_FIRST_LINE:
+                if c == pyparse.C_STRING_FIRST_LINE:
                     # after the first line of a string; do not indent at all
                     pass
-                elif c == PyParse.C_STRING_NEXT_LINES:
+                elif c == pyparse.C_STRING_NEXT_LINES:
                     # inside a string which started before this line;
                     # just mimic the current indent
                     text.insert("insert", indent)
-                elif c == PyParse.C_BRACKET:
+                elif c == pyparse.C_BRACKET:
                     # line up with the first (if any) element of the
                     # last open bracket structure; else indent one
                     # level beyond the indent of the line with the
                     # last open bracket
                     self.reindent_to(y.compute_bracket_indent())
-                elif c == PyParse.C_BACKSLASH:
+                elif c == pyparse.C_BACKSLASH:
                     # if more than one line in this stmt already, just
                     # mimic the current indent; else if initial line
                     # has a start on an assignment stmt, indent to
@@ -1657,7 +1670,7 @@
     keylist = keydefs.get(eventname)
     # issue10940: temporary workaround to prevent hang with OS X Cocoa Tk 8.5
     # if not keylist:
-    if (not keylist) or (macosxSupport.isCocoaTk() and eventname in {
+    if (not keylist) or (macosx.isCocoaTk() and eventname in {
                             "<<open-module>>",
                             "<<goto-line>>",
                             "<<change-indentwidth>>"}):
@@ -1692,7 +1705,7 @@
         filename = sys.argv[1]
     else:
         filename = None
-    macosxSupport.setupApp(root, None)
+    macosx.setupApp(root, None)
     edit = EditorWindow(root=root, filename=filename)
     edit.text.bind("<<close-all-windows>>", edit.close_event)
     # Does not stop error, neither does following
diff --git a/Lib/idlelib/filelist.py b/Lib/idlelib/filelist.py
index a9989a8..b5af90cc 100644
--- a/Lib/idlelib/filelist.py
+++ b/Lib/idlelib/filelist.py
@@ -6,7 +6,7 @@
 class FileList:
 
     # N.B. this import overridden in PyShellFileList.
-    from idlelib.EditorWindow import EditorWindow
+    from idlelib.editor import EditorWindow
 
     def __init__(self, root):
         self.root = root
@@ -111,7 +111,7 @@
 
 
 def _test():
-    from idlelib.EditorWindow import fixwordbreaks
+    from idlelib.editor import fixwordbreaks
     import sys
     root = Tk()
     fixwordbreaks(root)
diff --git a/Lib/idlelib/grep.py b/Lib/idlelib/grep.py
index 721b231..28132a8 100644
--- a/Lib/idlelib/grep.py
+++ b/Lib/idlelib/grep.py
@@ -4,14 +4,14 @@
 import sys
 from tkinter import StringVar, BooleanVar, Checkbutton  # for GrepDialog
 from tkinter import Tk, Text, Button, SEL, END  # for htest
-from idlelib import SearchEngine
-from idlelib.SearchDialogBase import SearchDialogBase
+from idlelib import searchengine
+from idlelib.searchbase import SearchDialogBase
 # Importing OutputWindow fails due to import loop
 # EditorWindow -> GrepDialop -> OutputWindow -> EditorWindow
 
 def grep(text, io=None, flist=None):
     root = text._root()
-    engine = SearchEngine.get(root)
+    engine = searchengine.get(root)
     if not hasattr(engine, "_grepdialog"):
         engine._grepdialog = GrepDialog(root, engine, flist)
     dialog = engine._grepdialog
@@ -67,7 +67,7 @@
         if not path:
             self.top.bell()
             return
-        from idlelib.OutputWindow import OutputWindow  # leave here!
+        from idlelib.outwin import OutputWindow  # leave here!
         save = sys.stdout
         try:
             sys.stdout = OutputWindow(self.flist)
@@ -131,7 +131,7 @@
 
 
 def _grep_dialog(parent):  # htest #
-    from idlelib.PyShell import PyShellFileList
+    from idlelib.pyshell import PyShellFileList
     root = Tk()
     root.title("Test GrepDialog")
     width, height, x, y = list(map(int, re.split('[x+]', parent.geometry())))
diff --git a/Lib/idlelib/help.py b/Lib/idlelib/help.py
index 4cb8c76..0093015 100644
--- a/Lib/idlelib/help.py
+++ b/Lib/idlelib/help.py
@@ -4,7 +4,7 @@
 
 Help => About IDLE: diplay About Idle dialog
 
-<to be moved here from aboutDialog.py>
+<to be moved here from help_about.py>
 
 
 Help => IDLE Help: Display help.html with proper formatting.
@@ -28,7 +28,7 @@
 from os.path import abspath, dirname, isfile, join
 from tkinter import Toplevel, Frame, Text, Scrollbar, Menu, Menubutton
 from tkinter import font as tkfont
-from idlelib.configHandler import idleConf
+from idlelib.config import idleConf
 
 use_ttk = False # until available to import
 if use_ttk:
diff --git a/Lib/idlelib/help_about.py b/Lib/idlelib/help_about.py
index 3112e6a..4b6c528 100644
--- a/Lib/idlelib/help_about.py
+++ b/Lib/idlelib/help_about.py
@@ -5,7 +5,7 @@
 import os
 from sys import version
 from tkinter import *
-from idlelib import textView
+from idlelib import textview
 
 class AboutDialog(Toplevel):
     """Modal about dialog for idle
@@ -135,11 +135,11 @@
     def display_printer_text(self, title, printer):
         printer._Printer__setup()
         text = '\n'.join(printer._Printer__lines)
-        textView.view_text(self, title, text)
+        textview.view_text(self, title, text)
 
     def display_file_text(self, title, filename, encoding=None):
         fn = os.path.join(os.path.abspath(os.path.dirname(__file__)), filename)
-        textView.view_file(self, title, fn, encoding)
+        textview.view_file(self, title, fn, encoding)
 
     def Ok(self, event=None):
         self.destroy()
diff --git a/Lib/idlelib/history.py b/Lib/idlelib/history.py
index 078af29..6068d4f 100644
--- a/Lib/idlelib/history.py
+++ b/Lib/idlelib/history.py
@@ -1,11 +1,11 @@
 "Implement Idle Shell history mechanism with History class"
 
-from idlelib.configHandler import idleConf
+from idlelib.config import idleConf
 
 class History:
     ''' Implement Idle Shell history mechanism.
 
-    store - Store source statement (called from PyShell.resetoutput).
+    store - Store source statement (called from pyshell.resetoutput).
     fetch - Fetch stored statement matching prefix already entered.
     history_next - Bound to <<history-next>> event (default Alt-N).
     history_prev - Bound to <<history-prev>> event (default Alt-P).
diff --git a/Lib/idlelib/hyperparser.py b/Lib/idlelib/hyperparser.py
index 77cb057..f904a39 100644
--- a/Lib/idlelib/hyperparser.py
+++ b/Lib/idlelib/hyperparser.py
@@ -7,7 +7,7 @@
 
 import string
 from keyword import iskeyword
-from idlelib import PyParse
+from idlelib import pyparse
 
 
 # all ASCII chars that may be in an identifier
@@ -30,7 +30,7 @@
         self.editwin = editwin
         self.text = text = editwin.text
 
-        parser = PyParse.Parser(editwin.indentwidth, editwin.tabwidth)
+        parser = pyparse.Parser(editwin.indentwidth, editwin.tabwidth)
 
         def index2line(index):
             return int(float(index))
diff --git a/Lib/idlelib/idle.py b/Lib/idlelib/idle.py
index a249557..c01cf99 100644
--- a/Lib/idlelib/idle.py
+++ b/Lib/idlelib/idle.py
@@ -7,5 +7,5 @@
 idlelib_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 sys.path.insert(0, idlelib_dir)
 
-import idlelib.PyShell
-idlelib.PyShell.main()
+import idlelib.pyshell
+idlelib.pyshell.main()
diff --git a/Lib/idlelib/idle.pyw b/Lib/idlelib/idle.pyw
index 142cb32..e73c049 100644
--- a/Lib/idlelib/idle.pyw
+++ b/Lib/idlelib/idle.pyw
@@ -1,10 +1,10 @@
 try:
-    import idlelib.PyShell
+    import idlelib.pyshell
 except ImportError:
-    # IDLE is not installed, but maybe PyShell is on sys.path:
-    from . import PyShell
+    # IDLE is not installed, but maybe pyshell is on sys.path:
+    from . import pyshell
     import os
-    idledir = os.path.dirname(os.path.abspath(PyShell.__file__))
+    idledir = os.path.dirname(os.path.abspath(pyshell.__file__))
     if idledir != os.getcwd():
         # We're not in the IDLE directory, help the subprocess find run.py
         pypath = os.environ.get('PYTHONPATH', '')
@@ -12,6 +12,6 @@
             os.environ['PYTHONPATH'] = pypath + ':' + idledir
         else:
             os.environ['PYTHONPATH'] = idledir
-    PyShell.main()
+    pyshell.main()
 else:
-    idlelib.PyShell.main()
+    idlelib.pyshell.main()
diff --git a/Lib/idlelib/idle_test/htest.py b/Lib/idlelib/idle_test/htest.py
index 58e62cb..4675645 100644
--- a/Lib/idlelib/idle_test/htest.py
+++ b/Lib/idlelib/idle_test/htest.py
@@ -59,19 +59,19 @@
 
 
 Modules and classes not being tested at the moment:
-PyShell.PyShellEditorWindow
-Debugger.Debugger
-AutoCompleteWindow.AutoCompleteWindow
-OutputWindow.OutputWindow (indirectly being tested with grep test)
+pyshell.PyShellEditorWindow
+debugger.Debugger
+autocomplete_w.AutoCompleteWindow
+outwin.OutputWindow (indirectly being tested with grep test)
 '''
 
 from importlib import import_module
-from idlelib.macosxSupport import _initializeTkVariantTests
+from idlelib.macosx import _initializeTkVariantTests
 import tkinter as tk
 
 AboutDialog_spec = {
-    'file': 'aboutDialog',
-    'kwds': {'title': 'aboutDialog test',
+    'file': 'help_about',
+    'kwds': {'title': 'help_about test',
              '_htest': True,
              },
     'msg': "Test every button. Ensure Python, TK and IDLE versions "
@@ -79,14 +79,14 @@
     }
 
 _calltip_window_spec = {
-    'file': 'CallTipWindow',
+    'file': 'calltip_w',
     'kwds': {},
     'msg': "Typing '(' should display a calltip.\n"
            "Typing ') should hide the calltip.\n"
     }
 
 _class_browser_spec = {
-    'file': 'ClassBrowser',
+    'file': 'browser',
     'kwds': {},
     'msg': "Inspect names of module, class(with superclass if "
            "applicable), methods and functions.\nToggle nested items.\n"
@@ -95,7 +95,7 @@
     }
 
 _color_delegator_spec = {
-    'file': 'ColorDelegator',
+    'file': 'colorizer',
     'kwds': {},
     'msg': "The text is sample Python code.\n"
            "Ensure components like comments, keywords, builtins,\n"
@@ -104,7 +104,7 @@
     }
 
 ConfigDialog_spec = {
-    'file': 'configDialog',
+    'file': 'configdialog',
     'kwds': {'title': 'ConfigDialogTest',
              '_htest': True,},
     'msg': "IDLE preferences dialog.\n"
@@ -121,7 +121,7 @@
 
 # TODO Improve message
 _dyn_option_menu_spec = {
-    'file': 'dynOptionMenuWidget',
+    'file': 'dynoption',
     'kwds': {},
     'msg': "Select one of the many options in the 'old option set'.\n"
            "Click the button to change the option set.\n"
@@ -130,14 +130,14 @@
 
 # TODO edit wrapper
 _editor_window_spec = {
-   'file': 'EditorWindow',
+   'file': 'editor',
     'kwds': {},
     'msg': "Test editor functions of interest.\n"
            "Best to close editor first."
     }
 
 GetCfgSectionNameDialog_spec = {
-    'file': 'configSectionNameDialog',
+    'file': 'config_sec',
     'kwds': {'title':'Get Name',
              'message':'Enter something',
              'used_names': {'abc'},
@@ -149,7 +149,7 @@
     }
 
 GetHelpSourceDialog_spec = {
-    'file': 'configHelpSourceEdit',
+    'file': 'config_help',
     'kwds': {'title': 'Get helpsource',
              '_htest': True},
     'msg': "Enter menu item name and help file path\n "
@@ -162,7 +162,7 @@
 
 # Update once issue21519 is resolved.
 GetKeysDialog_spec = {
-    'file': 'keybindingDialog',
+    'file': 'config_key',
     'kwds': {'title': 'Test keybindings',
              'action': 'find-again',
              'currentKeySequences': [''] ,
@@ -177,7 +177,7 @@
     }
 
 _grep_dialog_spec = {
-    'file': 'GrepDialog',
+    'file': 'grep',
     'kwds': {},
     'msg': "Click the 'Show GrepDialog' button.\n"
            "Test the various 'Find-in-files' functions.\n"
@@ -187,7 +187,7 @@
     }
 
 _io_binding_spec = {
-    'file': 'IOBinding',
+    'file': 'iomenu',
     'kwds': {},
     'msg': "Test the following bindings.\n"
            "<Control-o> to open file from dialog.\n"
@@ -200,7 +200,7 @@
     }
 
 _multi_call_spec = {
-    'file': 'MultiCall',
+    'file': 'multicall',
     'kwds': {},
     'msg': "The following actions should trigger a print to console or IDLE"
            " Shell.\nEntering and leaving the text area, key entry, "
@@ -210,14 +210,14 @@
     }
 
 _multistatus_bar_spec = {
-    'file': 'MultiStatusBar',
+    'file': 'statusbar',
     'kwds': {},
     'msg': "Ensure presence of multi-status bar below text area.\n"
            "Click 'Update Status' to change the multi-status text"
     }
 
 _object_browser_spec = {
-    'file': 'ObjectBrowser',
+    'file': 'debugobj',
     'kwds': {},
     'msg': "Double click on items upto the lowest level.\n"
            "Attributes of the objects and related information "
@@ -225,7 +225,7 @@
     }
 
 _path_browser_spec = {
-    'file': 'PathBrowser',
+    'file': 'pathbrowser',
     'kwds': {},
     'msg': "Test for correct display of all paths in sys.path.\n"
            "Toggle nested items upto the lowest level.\n"
@@ -234,7 +234,7 @@
     }
 
 _percolator_spec = {
-    'file': 'Percolator',
+    'file': 'percolator',
     'kwds': {},
     'msg': "There are two tracers which can be toggled using a checkbox.\n"
            "Toggling a tracer 'on' by checking it should print tracer"
@@ -245,7 +245,7 @@
     }
 
 _replace_dialog_spec = {
-    'file': 'ReplaceDialog',
+    'file': 'replace',
     'kwds': {},
     'msg': "Click the 'Replace' button.\n"
            "Test various replace options in the 'Replace dialog'.\n"
@@ -253,7 +253,7 @@
     }
 
 _search_dialog_spec = {
-    'file': 'SearchDialog',
+    'file': 'search',
     'kwds': {},
     'msg': "Click the 'Search' button.\n"
            "Test various search options in the 'Search dialog'.\n"
@@ -261,7 +261,7 @@
     }
 
 _scrolled_list_spec = {
-    'file': 'ScrolledList',
+    'file': 'scrolledlist',
     'kwds': {},
     'msg': "You should see a scrollable list of items\n"
            "Selecting (clicking) or double clicking an item "
@@ -277,7 +277,7 @@
     }
 
 _stack_viewer_spec = {
-    'file': 'StackViewer',
+    'file': 'stackviewer',
     'kwds': {},
     'msg': "A stacktrace for a NameError exception.\n"
            "Expand 'idlelib ...' and '<locals>'.\n"
@@ -295,8 +295,8 @@
     }
 
 TextViewer_spec = {
-    'file': 'textView',
-    'kwds': {'title': 'Test textView',
+    'file': 'textview',
+    'kwds': {'title': 'Test textview',
              'text':'The quick brown fox jumps over the lazy dog.\n'*35,
              '_htest': True},
     'msg': "Test for read-only property of text.\n"
@@ -304,21 +304,21 @@
      }
 
 _tooltip_spec = {
-    'file': 'ToolTip',
+    'file': 'tooltip',
     'kwds': {},
     'msg': "Place mouse cursor over both the buttons\n"
            "A tooltip should appear with some text."
     }
 
 _tree_widget_spec = {
-    'file': 'TreeWidget',
+    'file': 'tree',
     'kwds': {},
     'msg': "The canvas is scrollable.\n"
            "Click on folders upto to the lowest level."
     }
 
 _undo_delegator_spec = {
-    'file': 'UndoDelegator',
+    'file': 'undo',
     'kwds': {},
     'msg': "Click [Undo] to undo any action.\n"
            "Click [Redo] to redo any action.\n"
@@ -327,7 +327,7 @@
     }
 
 _widget_redirector_spec = {
-    'file': 'WidgetRedirector',
+    'file': 'redirector',
     'kwds': {},
     'msg': "Every text insert should be printed to the console."
            "or the IDLE shell."
diff --git a/Lib/idlelib/idle_test/mock_idle.py b/Lib/idlelib/idle_test/mock_idle.py
index 1672a34..c7b49ef 100644
--- a/Lib/idlelib/idle_test/mock_idle.py
+++ b/Lib/idlelib/idle_test/mock_idle.py
@@ -33,7 +33,7 @@
 
 
 class Editor:
-    '''Minimally imitate EditorWindow.EditorWindow class.
+    '''Minimally imitate editor.EditorWindow class.
     '''
     def __init__(self, flist=None, filename=None, key=None, root=None):
         self.text = Text()
@@ -46,7 +46,7 @@
 
 
 class UndoDelegator:
-    '''Minimally imitate UndoDelegator,UndoDelegator class.
+    '''Minimally imitate undo.UndoDelegator class.
     '''
     # A real undo block is only needed for user interaction.
     def undo_block_start(*args):
diff --git a/Lib/idlelib/idle_test/test_autocomplete.py b/Lib/idlelib/idle_test/test_autocomplete.py
index 3a2192e..833737e 100644
--- a/Lib/idlelib/idle_test/test_autocomplete.py
+++ b/Lib/idlelib/idle_test/test_autocomplete.py
@@ -2,9 +2,9 @@
 from test.support import requires
 from tkinter import Tk, Text
 
-import idlelib.AutoComplete as ac
-import idlelib.AutoCompleteWindow as acw
-import idlelib.macosxSupport as mac
+import idlelib.autocomplete as ac
+import idlelib.autocomplete_w as acw
+import idlelib.macosx as mac
 from idlelib.idle_test.mock_idle import Func
 from idlelib.idle_test.mock_tk import Event
 
diff --git a/Lib/idlelib/idle_test/test_autoexpand.py b/Lib/idlelib/idle_test/test_autoexpand.py
index 7ca941e..801976a 100644
--- a/Lib/idlelib/idle_test/test_autoexpand.py
+++ b/Lib/idlelib/idle_test/test_autoexpand.py
@@ -1,9 +1,9 @@
-"""Unit tests for idlelib.AutoExpand"""
+"""Unit tests for idlelib.autoexpand"""
 import unittest
 from test.support import requires
 from tkinter import Text, Tk
 #from idlelib.idle_test.mock_tk import Text
-from idlelib.AutoExpand import AutoExpand
+from idlelib.autoexpand import AutoExpand
 
 
 class Dummy_Editwin:
diff --git a/Lib/idlelib/idle_test/test_calltips.py b/Lib/idlelib/idle_test/test_calltips.py
index b2a733c..0b11602 100644
--- a/Lib/idlelib/idle_test/test_calltips.py
+++ b/Lib/idlelib/idle_test/test_calltips.py
@@ -1,5 +1,5 @@
 import unittest
-import idlelib.CallTips as ct
+import idlelib.calltips as ct
 import textwrap
 import types
 
diff --git a/Lib/idlelib/idle_test/test_config_help.py b/Lib/idlelib/idle_test/test_config_help.py
index 664f8ed..b89b4e3 100644
--- a/Lib/idlelib/idle_test/test_config_help.py
+++ b/Lib/idlelib/idle_test/test_config_help.py
@@ -1,7 +1,7 @@
-"""Unittests for idlelib.configHelpSourceEdit"""
+"""Unittests for idlelib.config_help.py"""
 import unittest
 from idlelib.idle_test.mock_tk import Var, Mbox, Entry
-from idlelib import configHelpSourceEdit as help_dialog_module
+from idlelib import config_help as help_dialog_module
 
 help_dialog = help_dialog_module.GetHelpSourceDialog
 
diff --git a/Lib/idlelib/idle_test/test_config_name.py b/Lib/idlelib/idle_test/test_config_sec.py
similarity index 94%
rename from Lib/idlelib/idle_test/test_config_name.py
rename to Lib/idlelib/idle_test/test_config_sec.py
index 40e72b9..a98b484 100644
--- a/Lib/idlelib/idle_test/test_config_name.py
+++ b/Lib/idlelib/idle_test/test_config_sec.py
@@ -1,7 +1,7 @@
-"""Unit tests for idlelib.configSectionNameDialog"""
+"""Unit tests for idlelib.config_sec"""
 import unittest
 from idlelib.idle_test.mock_tk import Var, Mbox
-from idlelib import configSectionNameDialog as name_dialog_module
+from idlelib import config_sec as name_dialog_module
 
 name_dialog = name_dialog_module.GetCfgSectionNameDialog
 
diff --git a/Lib/idlelib/idle_test/test_configdialog.py b/Lib/idlelib/idle_test/test_configdialog.py
index fab860b..3188432 100644
--- a/Lib/idlelib/idle_test/test_configdialog.py
+++ b/Lib/idlelib/idle_test/test_configdialog.py
@@ -1,4 +1,4 @@
-'''Unittests for idlelib/configHandler.py
+'''Unittests for idlelib/config.py
 
 Coverage: 46% just by creating dialog. The other half is change code.
 
@@ -6,8 +6,8 @@
 import unittest
 from test.support import requires
 from tkinter import Tk
-from idlelib.configDialog import ConfigDialog
-from idlelib.macosxSupport import _initializeTkVariantTests
+from idlelib.configdialog import ConfigDialog
+from idlelib.macosx import _initializeTkVariantTests
 
 
 class ConfigDialogTest(unittest.TestCase):
diff --git a/Lib/idlelib/idle_test/test_delegator.py b/Lib/idlelib/idle_test/test_delegator.py
index 1f0baa9..85624fb 100644
--- a/Lib/idlelib/idle_test/test_delegator.py
+++ b/Lib/idlelib/idle_test/test_delegator.py
@@ -1,5 +1,5 @@
 import unittest
-from idlelib.Delegator import Delegator
+from idlelib.delegator import Delegator
 
 class DelegatorTest(unittest.TestCase):
 
diff --git a/Lib/idlelib/idle_test/test_editor.py b/Lib/idlelib/idle_test/test_editor.py
index a31d26d..e9d29d4 100644
--- a/Lib/idlelib/idle_test/test_editor.py
+++ b/Lib/idlelib/idle_test/test_editor.py
@@ -1,6 +1,6 @@
 import unittest
 from tkinter import Tk, Text
-from idlelib.EditorWindow import EditorWindow
+from idlelib.editor import EditorWindow
 from test.support import requires
 
 class Editor_func_test(unittest.TestCase):
diff --git a/Lib/idlelib/idle_test/test_grep.py b/Lib/idlelib/idle_test/test_grep.py
index 0d8ff0d..6b54c13 100644
--- a/Lib/idlelib/idle_test/test_grep.py
+++ b/Lib/idlelib/idle_test/test_grep.py
@@ -1,5 +1,5 @@
 """ !Changing this line will break Test_findfile.test_found!
-Non-gui unit tests for idlelib.GrepDialog methods.
+Non-gui unit tests for grep.GrepDialog methods.
 dummy_command calls grep_it calls findfiles.
 An exception raised in one method will fail callers.
 Otherwise, tests are mostly independent.
@@ -8,7 +8,7 @@
 import unittest
 from test.support import captured_stdout
 from idlelib.idle_test.mock_tk import Var
-from idlelib.GrepDialog import GrepDialog
+from idlelib.grep import GrepDialog
 import re
 
 class Dummy_searchengine:
@@ -72,7 +72,7 @@
         self.assertTrue(lines[4].startswith('(Hint:'))
 
 class Default_commandTest(unittest.TestCase):
-    # To write this, mode OutputWindow import to top of GrepDialog
+    # To write this, move outwin import to top of GrepDialog
     # so it can be replaced by captured_stdout in class setup/teardown.
     pass
 
diff --git a/Lib/idlelib/idle_test/test_history.py b/Lib/idlelib/idle_test/test_history.py
index d7c3d70..6e8269c 100644
--- a/Lib/idlelib/idle_test/test_history.py
+++ b/Lib/idlelib/idle_test/test_history.py
@@ -4,8 +4,8 @@
 import tkinter as tk
 from tkinter import Text as tkText
 from idlelib.idle_test.mock_tk import Text as mkText
-from idlelib.IdleHistory import History
-from idlelib.configHandler import idleConf
+from idlelib.history import History
+from idlelib.config import idleConf
 
 line1 = 'a = 7'
 line2 = 'b = a'
diff --git a/Lib/idlelib/idle_test/test_hyperparser.py b/Lib/idlelib/idle_test/test_hyperparser.py
index edfc783..067e5b1 100644
--- a/Lib/idlelib/idle_test/test_hyperparser.py
+++ b/Lib/idlelib/idle_test/test_hyperparser.py
@@ -1,9 +1,9 @@
-"""Unittest for idlelib.HyperParser"""
+"""Unittest for idlelib.hyperparser.py."""
 import unittest
 from test.support import requires
 from tkinter import Tk, Text
-from idlelib.EditorWindow import EditorWindow
-from idlelib.HyperParser import HyperParser
+from idlelib.editor import EditorWindow
+from idlelib.hyperparser import HyperParser
 
 class DummyEditwin:
     def __init__(self, text):
diff --git a/Lib/idlelib/idle_test/test_iomenu.py b/Lib/idlelib/idle_test/test_iomenu.py
index e0e3b98..f8ff112 100644
--- a/Lib/idlelib/idle_test/test_iomenu.py
+++ b/Lib/idlelib/idle_test/test_iomenu.py
@@ -1,6 +1,6 @@
 import unittest
 import io
-from idlelib.PyShell import PseudoInputFile, PseudoOutputFile
+from idlelib.pyshell import PseudoInputFile, PseudoOutputFile
 
 
 class S(str):
diff --git a/Lib/idlelib/idle_test/test_paragraph.py b/Lib/idlelib/idle_test/test_paragraph.py
index f6039e6..6949bbb 100644
--- a/Lib/idlelib/idle_test/test_paragraph.py
+++ b/Lib/idlelib/idle_test/test_paragraph.py
@@ -1,7 +1,7 @@
-# Test the functions and main class method of FormatParagraph.py
+# Test the functions and main class method of paragraph.py
 import unittest
-from idlelib import FormatParagraph as fp
-from idlelib.EditorWindow import EditorWindow
+from idlelib import paragraph as fp
+from idlelib.editor import EditorWindow
 from tkinter import Tk, Text
 from test.support import requires
 
@@ -38,7 +38,7 @@
 
 
 class FindTest(unittest.TestCase):
-    """Test the find_paragraph function in FormatParagraph.
+    """Test the find_paragraph function in paragraph module.
 
     Using the runcase() function, find_paragraph() is called with 'mark' set at
     multiple indexes before and inside the test paragraph.
diff --git a/Lib/idlelib/idle_test/test_parenmatch.py b/Lib/idlelib/idle_test/test_parenmatch.py
index e153952..794a3aa 100644
--- a/Lib/idlelib/idle_test/test_parenmatch.py
+++ b/Lib/idlelib/idle_test/test_parenmatch.py
@@ -1,4 +1,4 @@
-"""Test idlelib.ParenMatch."""
+"""Test idlelib.parenmatch."""
 # This must currently be a gui test because ParenMatch methods use
 # several text methods not defined on idlelib.idle_test.mock_tk.Text.
 from test.support import requires
@@ -7,7 +7,7 @@
 import unittest
 from unittest.mock import Mock
 from tkinter import Tk, Text
-from idlelib.ParenMatch import ParenMatch
+from idlelib.parenmatch import ParenMatch
 
 class DummyEditwin:
     def __init__(self, text):
diff --git a/Lib/idlelib/idle_test/test_pathbrowser.py b/Lib/idlelib/idle_test/test_pathbrowser.py
index afb886f..813cbcc 100644
--- a/Lib/idlelib/idle_test/test_pathbrowser.py
+++ b/Lib/idlelib/idle_test/test_pathbrowser.py
@@ -2,13 +2,13 @@
 import os
 import sys
 import idlelib
-from idlelib import PathBrowser
+from idlelib import pathbrowser
 
 class PathBrowserTest(unittest.TestCase):
 
     def test_DirBrowserTreeItem(self):
         # Issue16226 - make sure that getting a sublist works
-        d = PathBrowser.DirBrowserTreeItem('')
+        d = pathbrowser.DirBrowserTreeItem('')
         d.GetSubList()
         self.assertEqual('', d.GetText())
 
@@ -17,11 +17,11 @@
         self.assertEqual(d.ispackagedir(dir + '/Icons'), False)
 
     def test_PathBrowserTreeItem(self):
-        p = PathBrowser.PathBrowserTreeItem()
+        p = pathbrowser.PathBrowserTreeItem()
         self.assertEqual(p.GetText(), 'sys.path')
         sub = p.GetSubList()
         self.assertEqual(len(sub), len(sys.path))
-        self.assertEqual(type(sub[0]), PathBrowser.DirBrowserTreeItem)
+        self.assertEqual(type(sub[0]), pathbrowser.DirBrowserTreeItem)
 
 if __name__ == '__main__':
     unittest.main(verbosity=2, exit=False)
diff --git a/Lib/idlelib/idle_test/test_percolator.py b/Lib/idlelib/idle_test/test_percolator.py
index bd2d666..dc3ed49 100644
--- a/Lib/idlelib/idle_test/test_percolator.py
+++ b/Lib/idlelib/idle_test/test_percolator.py
@@ -1,10 +1,10 @@
-'''Test Percolator'''
+'''Test percolator.py.'''
 from test.support import requires
 requires('gui')
 
 import unittest
 from tkinter import Text, Tk, END
-from idlelib.Percolator import Percolator, Delegator
+from idlelib.percolator import Percolator, Delegator
 
 
 class MyFilter(Delegator):
diff --git a/Lib/idlelib/idle_test/test_redirector.py b/Lib/idlelib/idle_test/test_redirector.py
index 6440561..998fd65 100644
--- a/Lib/idlelib/idle_test/test_redirector.py
+++ b/Lib/idlelib/idle_test/test_redirector.py
@@ -1,4 +1,4 @@
-"""Unittest for idlelib.WidgetRedirector
+"""Unittest for idlelib.redirector
 
 100% coverage
 """
@@ -6,7 +6,7 @@
 import unittest
 from idlelib.idle_test.mock_idle import Func
 from tkinter import Tk, Text, TclError
-from idlelib.WidgetRedirector import WidgetRedirector
+from idlelib.redirector import WidgetRedirector
 
 
 class InitCloseTest(unittest.TestCase):
diff --git a/Lib/idlelib/idle_test/test_replace.py b/Lib/idlelib/idle_test/test_replace.py
index 09669f8..acaae84 100644
--- a/Lib/idlelib/idle_test/test_replace.py
+++ b/Lib/idlelib/idle_test/test_replace.py
@@ -1,4 +1,4 @@
-"""Unittest for idlelib.ReplaceDialog"""
+"""Unittest for idlelib.replace.py"""
 from test.support import requires
 requires('gui')
 
@@ -6,8 +6,8 @@
 from unittest.mock import Mock
 from tkinter import Tk, Text
 from idlelib.idle_test.mock_tk import Mbox
-import idlelib.SearchEngine as se
-import idlelib.ReplaceDialog as rd
+import idlelib.searchengine as se
+import idlelib.replace as rd
 
 orig_mbox = se.tkMessageBox
 showerror = Mbox.showerror
diff --git a/Lib/idlelib/idle_test/test_rstrip.py b/Lib/idlelib/idle_test/test_rstrip.py
index 1c90b93..130e6be 100644
--- a/Lib/idlelib/idle_test/test_rstrip.py
+++ b/Lib/idlelib/idle_test/test_rstrip.py
@@ -1,5 +1,5 @@
 import unittest
-import idlelib.RstripExtension as rs
+import idlelib.rstrip as rs
 from idlelib.idle_test.mock_idle import Editor
 
 class rstripTest(unittest.TestCase):
@@ -21,7 +21,7 @@
     def test_rstrip_multiple(self):
         editor = Editor()
         #  Uncomment following to verify that test passes with real widgets.
-##        from idlelib.EditorWindow import EditorWindow as Editor
+##        from idlelib.editor import EditorWindow as Editor
 ##        from tkinter import Tk
 ##        editor = Editor(root=Tk())
         text = editor.text
diff --git a/Lib/idlelib/idle_test/test_search.py b/Lib/idlelib/idle_test/test_search.py
index 190c866..0735d84 100644
--- a/Lib/idlelib/idle_test/test_search.py
+++ b/Lib/idlelib/idle_test/test_search.py
@@ -1,4 +1,4 @@
-"""Test SearchDialog class in SearchDialogue.py"""
+"""Test SearchDialog class in idlelib.search.py"""
 
 # Does not currently test the event handler wrappers.
 # A usage test should simulate clicks and check hilighting.
@@ -11,8 +11,8 @@
 import unittest
 import tkinter as tk
 from tkinter import BooleanVar
-import idlelib.SearchEngine as se
-import idlelib.SearchDialog as sd
+import idlelib.searchengine as se
+import idlelib.search as sd
 
 
 class SearchDialogTest(unittest.TestCase):
diff --git a/Lib/idlelib/idle_test/test_searchbase.py b/Lib/idlelib/idle_test/test_searchbase.py
index 8036b91..5ff9476 100644
--- a/Lib/idlelib/idle_test/test_searchbase.py
+++ b/Lib/idlelib/idle_test/test_searchbase.py
@@ -1,4 +1,4 @@
-'''Unittests for idlelib/SearchDialogBase.py
+'''Unittests for idlelib/searchbase.py
 
 Coverage: 99%. The only thing not covered is inconsequential --
 testing skipping of suite when self.needwrapbutton is false.
@@ -7,8 +7,8 @@
 import unittest
 from test.support import requires
 from tkinter import Tk, Toplevel, Frame ##, BooleanVar, StringVar
-from idlelib import SearchEngine as se
-from idlelib import SearchDialogBase as sdb
+from idlelib import searchengine as se
+from idlelib import searchbase as sdb
 from idlelib.idle_test.mock_idle import Func
 ## from idlelib.idle_test.mock_tk import Var
 
diff --git a/Lib/idlelib/idle_test/test_searchengine.py b/Lib/idlelib/idle_test/test_searchengine.py
index edbd558..7e6f8b7 100644
--- a/Lib/idlelib/idle_test/test_searchengine.py
+++ b/Lib/idlelib/idle_test/test_searchengine.py
@@ -1,4 +1,4 @@
-'''Test functions and SearchEngine class in SearchEngine.py.'''
+'''Test functions and SearchEngine class in idlelib.searchengine.py.'''
 
 # With mock replacements, the module does not use any gui widgets.
 # The use of tk.Text is avoided (for now, until mock Text is improved)
@@ -10,7 +10,7 @@
 # from test.support import requires
 from tkinter import  BooleanVar, StringVar, TclError  # ,Tk, Text
 import tkinter.messagebox as tkMessageBox
-from idlelib import SearchEngine as se
+from idlelib import searchengine as se
 from idlelib.idle_test.mock_tk import Var, Mbox
 from idlelib.idle_test.mock_tk import Text as mockText
 
diff --git a/Lib/idlelib/idle_test/test_textview.py b/Lib/idlelib/idle_test/test_textview.py
index 68e5b82..bd0a46c 100644
--- a/Lib/idlelib/idle_test/test_textview.py
+++ b/Lib/idlelib/idle_test/test_textview.py
@@ -1,4 +1,4 @@
-'''Test the functions and main class method of textView.py.
+'''Test the functions and main class method of textview.py.
 
 Since all methods and functions create (or destroy) a TextViewer, which
 is a widget containing multiple widgets, all tests must be gui tests.
@@ -13,7 +13,7 @@
 import unittest
 import os
 from tkinter import Tk
-from idlelib import textView as tv
+from idlelib import textview as tv
 from idlelib.idle_test.mock_idle import Func
 from idlelib.idle_test.mock_tk import Mbox
 
diff --git a/Lib/idlelib/idle_test/test_undo.py b/Lib/idlelib/idle_test/test_undo.py
index 2657984..9a167c9 100644
--- a/Lib/idlelib/idle_test/test_undo.py
+++ b/Lib/idlelib/idle_test/test_undo.py
@@ -1,4 +1,4 @@
-"""Unittest for UndoDelegator in idlelib.UndoDelegator.
+"""Unittest for UndoDelegator in idlelib.undo.py.
 
 Coverage about 80% (retest).
 """
@@ -8,8 +8,8 @@
 import unittest
 from unittest.mock import Mock
 from tkinter import Text, Tk
-from idlelib.UndoDelegator import UndoDelegator
-from idlelib.Percolator import Percolator
+from idlelib.undo import UndoDelegator
+from idlelib.percolator import Percolator
 
 
 class UndoDelegatorTest(unittest.TestCase):
diff --git a/Lib/idlelib/idle_test/test_warning.py b/Lib/idlelib/idle_test/test_warning.py
index 18627dd..f3269f1 100644
--- a/Lib/idlelib/idle_test/test_warning.py
+++ b/Lib/idlelib/idle_test/test_warning.py
@@ -1,4 +1,4 @@
-'''Test warnings replacement in PyShell.py and run.py.
+'''Test warnings replacement in pyshell.py and run.py.
 
 This file could be expanded to include traceback overrides
 (in same two modules). If so, change name.
@@ -17,9 +17,9 @@
 running_in_idle = 'idle' in showwarning.__name__
 
 from idlelib import run
-from idlelib import PyShell as shell
+from idlelib import pyshell as shell
 
-# The following was generated from PyShell.idle_formatwarning
+# The following was generated from pyshell.idle_formatwarning
 # and checked as matching expectation.
 idlemsg = '''
 Warning (from warnings module):
diff --git a/Lib/idlelib/iomenu.py b/Lib/idlelib/iomenu.py
index 84f39a2..f6a7f14 100644
--- a/Lib/idlelib/iomenu.py
+++ b/Lib/idlelib/iomenu.py
@@ -10,7 +10,7 @@
 import tkinter.messagebox as tkMessageBox
 from tkinter.simpledialog import askstring
 
-from idlelib.configHandler import idleConf
+from idlelib.config import idleConf
 
 
 # Try setting the locale, so that we can find out
@@ -107,6 +107,9 @@
 
 
 class IOBinding:
+# One instance per editor Window so methods know which to save, close.
+# Open returns focus to self.editwin if aborted.
+# EditorWindow.open_module, others, belong here.
 
     def __init__(self, editwin):
         self.editwin = editwin
diff --git a/Lib/idlelib/macosx.py b/Lib/idlelib/macosx.py
index 268426f..1e16f2c 100644
--- a/Lib/idlelib/macosx.py
+++ b/Lib/idlelib/macosx.py
@@ -123,23 +123,23 @@
     # Due to a (mis-)feature of TkAqua the user will also see an empty Help
     # menu.
     from tkinter import Menu
-    from idlelib import Bindings
-    from idlelib import WindowList
+    from idlelib import mainmenu
+    from idlelib import windows
 
-    closeItem = Bindings.menudefs[0][1][-2]
+    closeItem = mainmenu.menudefs[0][1][-2]
 
     # Remove the last 3 items of the file menu: a separator, close window and
     # quit. Close window will be reinserted just above the save item, where
     # it should be according to the HIG. Quit is in the application menu.
-    del Bindings.menudefs[0][1][-3:]
-    Bindings.menudefs[0][1].insert(6, closeItem)
+    del mainmenu.menudefs[0][1][-3:]
+    mainmenu.menudefs[0][1].insert(6, closeItem)
 
     # Remove the 'About' entry from the help menu, it is in the application
     # menu
-    del Bindings.menudefs[-1][1][0:2]
+    del mainmenu.menudefs[-1][1][0:2]
     # Remove the 'Configure Idle' entry from the options menu, it is in the
     # application menu as 'Preferences'
-    del Bindings.menudefs[-2][1][0]
+    del mainmenu.menudefs[-2][1][0]
     menubar = Menu(root)
     root.configure(menu=menubar)
     menudict = {}
@@ -154,30 +154,30 @@
 
         if end > 0:
             menu.delete(0, end)
-        WindowList.add_windows_to_menu(menu)
-    WindowList.register_callback(postwindowsmenu)
+        windows.add_windows_to_menu(menu)
+    Windows.register_callback(postwindowsmenu)
 
     def about_dialog(event=None):
         "Handle Help 'About IDLE' event."
-        # Synchronize with EditorWindow.EditorWindow.about_dialog.
-        from idlelib import aboutDialog
-        aboutDialog.AboutDialog(root, 'About IDLE')
+        # Synchronize with editor.EditorWindow.about_dialog.
+        from idlelib import help_about
+        help_about.AboutDialog(root, 'About IDLE')
 
     def config_dialog(event=None):
         "Handle Options 'Configure IDLE' event."
-        # Synchronize with EditorWindow.EditorWindow.config_dialog.
-        from idlelib import configDialog
+        # Synchronize with editor.EditorWindow.config_dialog.
+        from idlelib import configdialog
 
         # Ensure that the root object has an instance_dict attribute,
         # mirrors code in EditorWindow (although that sets the attribute
         # on an EditorWindow instance that is then passed as the first
         # argument to ConfigDialog)
         root.instance_dict = flist.inversedict
-        configDialog.ConfigDialog(root, 'Settings')
+        configdialog.ConfigDialog(root, 'Settings')
 
     def help_dialog(event=None):
         "Handle Help 'IDLE Help' event."
-        # Synchronize with EditorWindow.EditorWindow.help_dialog.
+        # Synchronize with editor.EditorWindow.help_dialog.
         from idlelib import help
         help.show_idlehelp(root)
 
@@ -197,7 +197,7 @@
         menudict['application'] = menu = Menu(menubar, name='apple',
                                               tearoff=0)
         menubar.add_cascade(label='IDLE', menu=menu)
-        Bindings.menudefs.insert(0,
+        mainmenu.menudefs.insert(0,
             ('application', [
                 ('About IDLE', '<<about-idle>>'),
                     None,
@@ -205,7 +205,7 @@
         tkversion = root.tk.eval('info patchlevel')
         if tuple(map(int, tkversion.split('.'))) < (8, 4, 14):
             # for earlier AquaTk versions, supply a Preferences menu item
-            Bindings.menudefs[0][1].append(
+            mainmenu.menudefs[0][1].append(
                     ('_Preferences....', '<<open-config-dialog>>'),
                 )
     if isCocoaTk():
@@ -214,12 +214,12 @@
         # replace default "Help" item in Help menu
         root.createcommand('::tk::mac::ShowHelp', help_dialog)
         # remove redundant "IDLE Help" from menu
-        del Bindings.menudefs[-1][1][0]
+        del mainmenu.menudefs[-1][1][0]
 
 def setupApp(root, flist):
     """
     Perform initial OS X customizations if needed.
-    Called from PyShell.main() after initial calls to Tk()
+    Called from pyshell.main() after initial calls to Tk()
 
     There are currently three major versions of Tk in use on OS X:
         1. Aqua Cocoa Tk (native default since OS X 10.6)
diff --git a/Lib/idlelib/mainmenu.py b/Lib/idlelib/mainmenu.py
index ab25ff1..965ada3 100644
--- a/Lib/idlelib/mainmenu.py
+++ b/Lib/idlelib/mainmenu.py
@@ -10,9 +10,9 @@
 """
 from importlib.util import find_spec
 
-from idlelib.configHandler import idleConf
+from idlelib.config import idleConf
 
-#   Warning: menudefs is altered in macosxSupport.overrideRootMenu()
+#   Warning: menudefs is altered in macosx.overrideRootMenu()
 #   after it is determined that an OS X Aqua Tk is in use,
 #   which cannot be done until after Tk() is first called.
 #   Do not alter the 'file', 'options', or 'help' cascades here
diff --git a/Lib/idlelib/outwin.py b/Lib/idlelib/outwin.py
index e614f9b..b3bc786 100644
--- a/Lib/idlelib/outwin.py
+++ b/Lib/idlelib/outwin.py
@@ -1,8 +1,8 @@
 from tkinter import *
-from idlelib.EditorWindow import EditorWindow
+from idlelib.editor import EditorWindow
 import re
 import tkinter.messagebox as tkMessageBox
-from idlelib import IOBinding
+from idlelib import iomenu
 
 class OutputWindow(EditorWindow):
 
@@ -36,7 +36,7 @@
 
     def write(self, s, tags=(), mark="insert"):
         if isinstance(s, (bytes, bytes)):
-            s = s.decode(IOBinding.encoding, "replace")
+            s = s.decode(iomenu.encoding, "replace")
         self.text.insert(mark, s, tags)
         self.text.see(mark)
         self.text.update()
diff --git a/Lib/idlelib/paragraph.py b/Lib/idlelib/paragraph.py
index 7a9d185..0323b53 100644
--- a/Lib/idlelib/paragraph.py
+++ b/Lib/idlelib/paragraph.py
@@ -16,7 +16,7 @@
 """
 
 import re
-from idlelib.configHandler import idleConf
+from idlelib.config import idleConf
 
 class FormatParagraph:
 
@@ -191,5 +191,5 @@
 
 if __name__ == "__main__":
     import unittest
-    unittest.main('idlelib.idle_test.test_formatparagraph',
+    unittest.main('idlelib.idle_test.test_paragraph',
             verbosity=2, exit=False)
diff --git a/Lib/idlelib/parenmatch.py b/Lib/idlelib/parenmatch.py
index 19bad8c..e98fac1 100644
--- a/Lib/idlelib/parenmatch.py
+++ b/Lib/idlelib/parenmatch.py
@@ -5,8 +5,8 @@
 parentheses, square brackets, and curly braces.
 """
 
-from idlelib.HyperParser import HyperParser
-from idlelib.configHandler import idleConf
+from idlelib.hyperparser import HyperParser
+from idlelib.config import idleConf
 
 _openers = {')':'(',']':'[','}':'{'}
 CHECK_DELAY = 100 # miliseconds
diff --git a/Lib/idlelib/pathbrowser.py b/Lib/idlelib/pathbrowser.py
index 9ab7632..966af4b 100644
--- a/Lib/idlelib/pathbrowser.py
+++ b/Lib/idlelib/pathbrowser.py
@@ -2,9 +2,9 @@
 import sys
 import importlib.machinery
 
-from idlelib.TreeWidget import TreeItem
-from idlelib.ClassBrowser import ClassBrowser, ModuleBrowserTreeItem
-from idlelib.PyShell import PyShellFileList
+from idlelib.tree import TreeItem
+from idlelib.browser import ClassBrowser, ModuleBrowserTreeItem
+from idlelib.pyshell import PyShellFileList
 
 
 class PathBrowser(ClassBrowser):
diff --git a/Lib/idlelib/percolator.py b/Lib/idlelib/percolator.py
index b8be2aa..2271445 100644
--- a/Lib/idlelib/percolator.py
+++ b/Lib/idlelib/percolator.py
@@ -1,5 +1,5 @@
-from idlelib.WidgetRedirector import WidgetRedirector
-from idlelib.Delegator import Delegator
+from idlelib.redirector import WidgetRedirector
+from idlelib.delegator import Delegator
 
 
 class Percolator:
diff --git a/Lib/idlelib/pyshell.py b/Lib/idlelib/pyshell.py
index 1bcc9b6..8341cd9 100755
--- a/Lib/idlelib/pyshell.py
+++ b/Lib/idlelib/pyshell.py
@@ -24,16 +24,16 @@
     sys.exit(1)
 import tkinter.messagebox as tkMessageBox
 
-from idlelib.EditorWindow import EditorWindow, fixwordbreaks
-from idlelib.FileList import FileList
-from idlelib.ColorDelegator import ColorDelegator
-from idlelib.UndoDelegator import UndoDelegator
-from idlelib.OutputWindow import OutputWindow
-from idlelib.configHandler import idleConf
+from idlelib.editor import EditorWindow, fixwordbreaks
+from idlelib.filelist import FileList
+from idlelib.colorizer import ColorDelegator
+from idlelib.undo import UndoDelegator
+from idlelib.outwin import OutputWindow
+from idlelib.config import idleConf
 from idlelib import rpc
-from idlelib import Debugger
-from idlelib import RemoteDebugger
-from idlelib import macosxSupport
+from idlelib import debugger
+from idlelib import debugger_r
+from idlelib import macosx
 
 HOST = '127.0.0.1' # python execution server on localhost loopback
 PORT = 0  # someday pass in host, port for remote debug capability
@@ -410,7 +410,7 @@
         # run from the IDLE source directory.
         del_exitf = idleConf.GetOption('main', 'General', 'delete-exitfunc',
                                        default=False, type='bool')
-        if __name__ == 'idlelib.PyShell':
+        if __name__ == 'idlelib.pyshell':
             command = "__import__('idlelib.run').run.main(%r)" % (del_exitf,)
         else:
             command = "__import__('run').main(%r)" % (del_exitf,)
@@ -468,7 +468,7 @@
         if debug:
             try:
                 # Only close subprocess debugger, don't unregister gui_adap!
-                RemoteDebugger.close_subprocess_debugger(self.rpcclt)
+                debugger_r.close_subprocess_debugger(self.rpcclt)
             except:
                 pass
         # Kill subprocess, spawn a new one, accept connection.
@@ -497,7 +497,7 @@
         # restart subprocess debugger
         if debug:
             # Restarted debugger connects to current instance of debug GUI
-            RemoteDebugger.restart_subprocess_debugger(self.rpcclt)
+            debugger_r.restart_subprocess_debugger(self.rpcclt)
             # reload remote debugger breakpoints for all PyShellEditWindows
             debug.load_breakpoints()
         self.compile.compiler.flags = self.original_compiler_flags
@@ -578,7 +578,7 @@
                 if self.tkconsole.getvar("<<toggle-jit-stack-viewer>>"):
                     self.remote_stack_viewer()
             elif how == "ERROR":
-                errmsg = "PyShell.ModifiedInterpreter: Subprocess ERROR:\n"
+                errmsg = "pyshell.ModifiedInterpreter: Subprocess ERROR:\n"
                 print(errmsg, what, file=sys.__stderr__)
                 print(errmsg, what, file=console)
             # we received a response to the currently active seq number:
@@ -613,13 +613,13 @@
         return
 
     def remote_stack_viewer(self):
-        from idlelib import RemoteObjectBrowser
+        from idlelib import debugobj_r
         oid = self.rpcclt.remotequeue("exec", "stackviewer", ("flist",), {})
         if oid is None:
             self.tkconsole.root.bell()
             return
-        item = RemoteObjectBrowser.StubObjectTreeItem(self.rpcclt, oid)
-        from idlelib.TreeWidget import ScrolledCanvas, TreeNode
+        item = debugobj_r.StubObjectTreeItem(self.rpcclt, oid)
+        from idlelib.tree import ScrolledCanvas, TreeNode
         top = Toplevel(self.tkconsole.root)
         theme = idleConf.CurrentTheme()
         background = idleConf.GetHighlight(theme, 'normal')['background']
@@ -662,9 +662,9 @@
         # at the moment, InteractiveInterpreter expects str
         assert isinstance(source, str)
         #if isinstance(source, str):
-        #    from idlelib import IOBinding
+        #    from idlelib import iomenu
         #    try:
-        #        source = source.encode(IOBinding.encoding)
+        #        source = source.encode(iomenu.encoding)
         #    except UnicodeError:
         #        self.tkconsole.resetoutput()
         #        self.write("Unsupported characters in input\n")
@@ -850,7 +850,7 @@
 
 
     # New classes
-    from idlelib.IdleHistory import History
+    from idlelib.history import History
 
     def __init__(self, flist=None):
         if use_subprocess:
@@ -888,11 +888,11 @@
         self.save_stdout = sys.stdout
         self.save_stderr = sys.stderr
         self.save_stdin = sys.stdin
-        from idlelib import IOBinding
-        self.stdin = PseudoInputFile(self, "stdin", IOBinding.encoding)
-        self.stdout = PseudoOutputFile(self, "stdout", IOBinding.encoding)
-        self.stderr = PseudoOutputFile(self, "stderr", IOBinding.encoding)
-        self.console = PseudoOutputFile(self, "console", IOBinding.encoding)
+        from idlelib import iomenu
+        self.stdin = PseudoInputFile(self, "stdin", iomenu.encoding)
+        self.stdout = PseudoOutputFile(self, "stdout", iomenu.encoding)
+        self.stderr = PseudoOutputFile(self, "stderr", iomenu.encoding)
+        self.console = PseudoOutputFile(self, "console", iomenu.encoding)
         if not use_subprocess:
             sys.stdout = self.stdout
             sys.stderr = self.stderr
@@ -900,7 +900,7 @@
         try:
             # page help() text to shell.
             import pydoc # import must be done here to capture i/o rebinding.
-            # XXX KBK 27Dec07 use a textView someday, but must work w/o subproc
+            # XXX KBK 27Dec07 use TextViewer someday, but must work w/o subproc
             pydoc.pager = pydoc.plainpager
         except:
             sys.stderr = sys.__stderr__
@@ -954,7 +954,7 @@
             self.interp.setdebugger(None)
             db.close()
             if self.interp.rpcclt:
-                RemoteDebugger.close_remote_debugger(self.interp.rpcclt)
+                debugger_r.close_remote_debugger(self.interp.rpcclt)
             self.resetoutput()
             self.console.write("[DEBUG OFF]\n")
             sys.ps1 = ">>> "
@@ -963,10 +963,10 @@
 
     def open_debugger(self):
         if self.interp.rpcclt:
-            dbg_gui = RemoteDebugger.start_remote_debugger(self.interp.rpcclt,
+            dbg_gui = debugger_r.start_remote_debugger(self.interp.rpcclt,
                                                            self)
         else:
-            dbg_gui = Debugger.Debugger(self)
+            dbg_gui = debugger.Debugger(self)
         self.interp.setdebugger(dbg_gui)
         dbg_gui.load_breakpoints()
         sys.ps1 = "[DEBUG ON]\n>>> "
@@ -1241,7 +1241,7 @@
                 "(sys.last_traceback is not defined)",
                 parent=self.text)
             return
-        from idlelib.StackViewer import StackBrowser
+        from idlelib.stackviewer import StackBrowser
         StackBrowser(self.root, self.flist)
 
     def view_restart_mark(self, event=None):
@@ -1546,9 +1546,9 @@
     fixwordbreaks(root)
     root.withdraw()
     flist = PyShellFileList(root)
-    macosxSupport.setupApp(root, flist)
+    macosx.setupApp(root, flist)
 
-    if macosxSupport.isAquaTk():
+    if macosx.isAquaTk():
         # There are some screwed up <2> class bindings for text
         # widgets defined in Tk which we need to do away with.
         # See issue #24801.
@@ -1569,7 +1569,7 @@
         shell = flist.open_shell()
         if not shell:
             return # couldn't open shell
-        if macosxSupport.isAquaTk() and flist.dict:
+        if macosx.isAquaTk() and flist.dict:
             # On OSX: when the user has double-clicked on a file that causes
             # IDLE to be launched the shell window will open just in front of
             # the file she wants to see. Lower the interpreter window when
@@ -1603,7 +1603,7 @@
         # check for problematic OS X Tk versions and print a warning
         # message in the IDLE shell window; this is less intrusive
         # than always opening a separate window.
-        tkversionwarning = macosxSupport.tkVersionWarning(root)
+        tkversionwarning = macosx.tkVersionWarning(root)
         if tkversionwarning:
             shell.interp.runcommand("print('%s')" % tkversionwarning)
 
@@ -1613,7 +1613,7 @@
     capture_warnings(False)
 
 if __name__ == "__main__":
-    sys.modules['PyShell'] = sys.modules['__main__']
+    sys.modules['pyshell'] = sys.modules['__main__']
     main()
 
 capture_warnings(False)  # Make sure turned off; see issue 18081
diff --git a/Lib/idlelib/redirector.py b/Lib/idlelib/redirector.py
index b66be9e..5ca7a2d 100644
--- a/Lib/idlelib/redirector.py
+++ b/Lib/idlelib/redirector.py
@@ -104,7 +104,7 @@
 
         Note that if a registered function is called, the operation is not
         passed through to Tk.  Apply the function returned by self.register()
-        to *args to accomplish that.  For an example, see ColorDelegator.py.
+        to *args to accomplish that.  For an example, see colorizer.py.
 
         '''
         m = self._operations.get(operation)
diff --git a/Lib/idlelib/replace.py b/Lib/idlelib/replace.py
index f2ea22e..589b814 100644
--- a/Lib/idlelib/replace.py
+++ b/Lib/idlelib/replace.py
@@ -5,8 +5,8 @@
 """
 from tkinter import *
 
-from idlelib import SearchEngine
-from idlelib.SearchDialogBase import SearchDialogBase
+from idlelib import searchengine
+from idlelib.searchbase import SearchDialogBase
 import re
 
 
@@ -14,7 +14,7 @@
     """Returns a singleton ReplaceDialog instance.The single dialog
      saves user entries and preferences across instances."""
     root = text._root()
-    engine = SearchEngine.get(root)
+    engine = searchengine.get(root)
     if not hasattr(engine, "_replacedialog"):
         engine._replacedialog = ReplaceDialog(root, engine)
     dialog = engine._replacedialog
@@ -164,7 +164,7 @@
             pos = None
         if not pos:
             first = last = pos = text.index("insert")
-        line, col = SearchEngine.get_line_col(pos)
+        line, col = searchengine.get_line_col(pos)
         chars = text.get("%d.0" % line, "%d.0" % (line+1))
         m = prog.match(chars, col)
         if not prog:
diff --git a/Lib/idlelib/run.py b/Lib/idlelib/run.py
index 595e7bc..eb34944 100644
--- a/Lib/idlelib/run.py
+++ b/Lib/idlelib/run.py
@@ -7,15 +7,15 @@
 import queue
 import tkinter
 
-from idlelib import CallTips
-from idlelib import AutoComplete
+from idlelib import calltips
+from idlelib import autocomplete
 
-from idlelib import RemoteDebugger
-from idlelib import RemoteObjectBrowser
-from idlelib import StackViewer
+from idlelib import debugger_r
+from idlelib import debugobj_r
+from idlelib import stackviewer
 from idlelib import rpc
-from idlelib import PyShell
-from idlelib import IOBinding
+from idlelib import pyshell
+from idlelib import iomenu
 
 import __main__
 
@@ -32,7 +32,7 @@
     if file is None:
         file = sys.stderr
     try:
-        file.write(PyShell.idle_formatwarning(
+        file.write(pyshell.idle_formatwarning(
                 message, category, filename, lineno, line))
     except IOError:
         pass # the file (probably stderr) is invalid - this warning gets lost.
@@ -82,7 +82,7 @@
     MyHandler object.  That reference is saved as attribute rpchandler of the
     Executive instance.  The Executive methods have access to the reference and
     can pass it on to entities that they command
-    (e.g. RemoteDebugger.Debugger.start_debugger()).  The latter, in turn, can
+    (e.g. debugger_r.Debugger.start_debugger()).  The latter, in turn, can
     call MyHandler(SocketIO) register/unregister methods via the reference to
     register and unregister themselves.
 
@@ -204,7 +204,7 @@
             tbe = traceback.extract_tb(tb)
             print('Traceback (most recent call last):', file=efile)
             exclude = ("run.py", "rpc.py", "threading.py", "queue.py",
-                       "RemoteDebugger.py", "bdb.py")
+                       "debugger_r.py", "bdb.py")
             cleanup_traceback(tbe, exclude)
             traceback.print_list(tbe, file=efile)
         lines = traceback.format_exception_only(typ, exc)
@@ -298,12 +298,12 @@
         executive = Executive(self)
         self.register("exec", executive)
         self.console = self.get_remote_proxy("console")
-        sys.stdin = PyShell.PseudoInputFile(self.console, "stdin",
-                IOBinding.encoding)
-        sys.stdout = PyShell.PseudoOutputFile(self.console, "stdout",
-                IOBinding.encoding)
-        sys.stderr = PyShell.PseudoOutputFile(self.console, "stderr",
-                IOBinding.encoding)
+        sys.stdin = pyshell.PseudoInputFile(self.console, "stdin",
+                iomenu.encoding)
+        sys.stdout = pyshell.PseudoOutputFile(self.console, "stdout",
+                iomenu.encoding)
+        sys.stderr = pyshell.PseudoOutputFile(self.console, "stderr",
+                iomenu.encoding)
 
         sys.displayhook = rpc.displayhook
         # page help() text to shell.
@@ -339,8 +339,8 @@
     def __init__(self, rpchandler):
         self.rpchandler = rpchandler
         self.locals = __main__.__dict__
-        self.calltip = CallTips.CallTips()
-        self.autocomplete = AutoComplete.AutoComplete()
+        self.calltip = calltips.CallTips()
+        self.autocomplete = autocomplete.AutoComplete()
 
     def runcode(self, code):
         global interruptable
@@ -372,7 +372,7 @@
             thread.interrupt_main()
 
     def start_the_debugger(self, gui_adap_oid):
-        return RemoteDebugger.start_debugger(self.rpchandler, gui_adap_oid)
+        return debugger_r.start_debugger(self.rpchandler, gui_adap_oid)
 
     def stop_the_debugger(self, idb_adap_oid):
         "Unregister the Idb Adapter.  Link objects and Idb then subject to GC"
@@ -396,7 +396,7 @@
             tb = tb.tb_next
         sys.last_type = typ
         sys.last_value = val
-        item = StackViewer.StackTreeItem(flist, tb)
-        return RemoteObjectBrowser.remote_object_tree_item(item)
+        item = stackviewer.StackTreeItem(flist, tb)
+        return debugobj_r.remote_object_tree_item(item)
 
 capture_warnings(False)  # Make sure turned off; see issue 18081
diff --git a/Lib/idlelib/runscript.py b/Lib/idlelib/runscript.py
index 5cb818d..7e7524a 100644
--- a/Lib/idlelib/runscript.py
+++ b/Lib/idlelib/runscript.py
@@ -21,10 +21,10 @@
 import tabnanny
 import tokenize
 import tkinter.messagebox as tkMessageBox
-from idlelib import PyShell
+from idlelib import pyshell
 
-from idlelib.configHandler import idleConf
-from idlelib import macosxSupport
+from idlelib.config import idleConf
+from idlelib import macosx
 
 indent_message = """Error: Inconsistent indentation detected!
 
@@ -46,12 +46,12 @@
 
     def __init__(self, editwin):
         self.editwin = editwin
-        # Provide instance variables referenced by Debugger
+        # Provide instance variables referenced by debugger
         # XXX This should be done differently
         self.flist = self.editwin.flist
         self.root = self.editwin.root
 
-        if macosxSupport.isCocoaTk():
+        if macosx.isCocoaTk():
             self.editwin.text_frame.bind('<<run-module-event-2>>', self._run_module_event)
 
     def check_module_event(self, event):
@@ -112,7 +112,7 @@
             shell.set_warning_stream(saved_stream)
 
     def run_module_event(self, event):
-        if macosxSupport.isCocoaTk():
+        if macosx.isCocoaTk():
             # Tk-Cocoa in MacOSX is broken until at least
             # Tk 8.5.9, and without this rather
             # crude workaround IDLE would hang when a user
@@ -142,7 +142,7 @@
         if not self.tabnanny(filename):
             return 'break'
         interp = self.shell.interp
-        if PyShell.use_subprocess:
+        if pyshell.use_subprocess:
             interp.restart_subprocess(with_cwd=False, filename=
                         self.editwin._filename_to_unicode(filename))
         dirname = os.path.dirname(filename)
@@ -161,7 +161,7 @@
         interp.prepend_syspath(filename)
         # XXX KBK 03Jul04 When run w/o subprocess, runtime warnings still
         #         go to __stderr__.  With subprocess, they go to the shell.
-        #         Need to change streams in PyShell.ModifiedInterpreter.
+        #         Need to change streams in pyshell.ModifiedInterpreter.
         interp.runcode(code)
         return 'break'
 
diff --git a/Lib/idlelib/scrolledlist.py b/Lib/idlelib/scrolledlist.py
index 53576b5..80df0f8 100644
--- a/Lib/idlelib/scrolledlist.py
+++ b/Lib/idlelib/scrolledlist.py
@@ -1,5 +1,5 @@
 from tkinter import *
-from idlelib import macosxSupport
+from idlelib import macosx
 
 class ScrolledList:
 
@@ -23,7 +23,7 @@
         # Bind events to the list box
         listbox.bind("<ButtonRelease-1>", self.click_event)
         listbox.bind("<Double-ButtonRelease-1>", self.double_click_event)
-        if macosxSupport.isAquaTk():
+        if macosx.isAquaTk():
             listbox.bind("<ButtonPress-2>", self.popup_event)
             listbox.bind("<Control-Button-1>", self.popup_event)
         else:
diff --git a/Lib/idlelib/search.py b/Lib/idlelib/search.py
index 765d53f..a609fd9 100644
--- a/Lib/idlelib/search.py
+++ b/Lib/idlelib/search.py
@@ -1,12 +1,12 @@
 from tkinter import *
 
-from idlelib import SearchEngine
-from idlelib.SearchDialogBase import SearchDialogBase
+from idlelib import searchengine
+from idlelib.searchbase import SearchDialogBase
 
 def _setup(text):
     "Create or find the singleton SearchDialog instance."
     root = text._root()
-    engine = SearchEngine.get(root)
+    engine = searchengine.get(root)
     if not hasattr(engine, "_searchdialog"):
         engine._searchdialog = SearchDialog(root, engine)
     return engine._searchdialog
diff --git a/Lib/idlelib/searchbase.py b/Lib/idlelib/searchbase.py
index 5fa84e2..9206bf5 100644
--- a/Lib/idlelib/searchbase.py
+++ b/Lib/idlelib/searchbase.py
@@ -125,7 +125,7 @@
     def create_option_buttons(self):
         '''Return (filled frame, options) for testing.
 
-        Options is a list of SearchEngine booleanvar, label pairs.
+        Options is a list of searchengine booleanvar, label pairs.
         A gridded frame from make_frame is filled with a Checkbutton
         for each pair, bound to the var, with the corresponding label.
         '''
diff --git a/Lib/idlelib/searchengine.py b/Lib/idlelib/searchengine.py
index 37883bf..2e3700e 100644
--- a/Lib/idlelib/searchengine.py
+++ b/Lib/idlelib/searchengine.py
@@ -57,7 +57,7 @@
 
     def setcookedpat(self, pat):
         "Set pattern after escaping if re."
-        # called only in SearchDialog.py: 66
+        # called only in search.py: 66
         if self.isre():
             pat = re.escape(pat)
         self.setpat(pat)
diff --git a/Lib/idlelib/stackviewer.py b/Lib/idlelib/stackviewer.py
index ccc755c..5c188f0 100644
--- a/Lib/idlelib/stackviewer.py
+++ b/Lib/idlelib/stackviewer.py
@@ -4,9 +4,9 @@
 import re
 import tkinter as tk
 
-from idlelib.TreeWidget import TreeNode, TreeItem, ScrolledCanvas
-from idlelib.ObjectBrowser import ObjectTreeItem, make_objecttreeitem
-from idlelib.PyShell import PyShellFileList
+from idlelib.tree import TreeNode, TreeItem, ScrolledCanvas
+from idlelib.debugobj import ObjectTreeItem, make_objecttreeitem
+from idlelib.pyshell import PyShellFileList
 
 def StackBrowser(root, flist=None, tb=None, top=None):
     if top is None:
diff --git a/Lib/idlelib/tooltip.py b/Lib/idlelib/tooltip.py
index 964107e..c3eafed 100644
--- a/Lib/idlelib/tooltip.py
+++ b/Lib/idlelib/tooltip.py
@@ -1,4 +1,4 @@
-# general purpose 'tooltip' routines - currently unused in idlefork
+# general purpose 'tooltip' routines - currently unused in idlelib
 # (although the 'calltips' extension is partly based on this code)
 # may be useful for some purposes in (or almost in ;) the current project scope
 # Ideas gleaned from PySol
@@ -76,7 +76,7 @@
         for item in self.items:
             listbox.insert(END, item)
 
-def _tooltip(parent):
+def _tooltip(parent):  # htest #
     root = Tk()
     root.title("Test tooltip")
     width, height, x, y = list(map(int, re.split('[x+]', parent.geometry())))
diff --git a/Lib/idlelib/tree.py b/Lib/idlelib/tree.py
index a19578f..08cc637 100644
--- a/Lib/idlelib/tree.py
+++ b/Lib/idlelib/tree.py
@@ -17,8 +17,8 @@
 import os
 from tkinter import *
 
-from idlelib import ZoomHeight
-from idlelib.configHandler import idleConf
+from idlelib import zoomheight
+from idlelib.config import idleConf
 
 ICONDIR = "Icons"
 
@@ -445,7 +445,7 @@
         self.canvas.yview_scroll(1, "unit")
         return "break"
     def zoom_height(self, event):
-        ZoomHeight.zoom_height(self.master)
+        zoomheight.zoom_height(self.master)
         return "break"
 
 
diff --git a/Lib/idlelib/undo.py b/Lib/idlelib/undo.py
index 1c2502d..3e94b69 100644
--- a/Lib/idlelib/undo.py
+++ b/Lib/idlelib/undo.py
@@ -1,7 +1,7 @@
 import string
 from tkinter import *
 
-from idlelib.Delegator import Delegator
+from idlelib.delegator import Delegator
 
 #$ event <<redo>>
 #$ win <Control-y>
@@ -340,7 +340,7 @@
 def _undo_delegator(parent):  # htest #
     import re
     import tkinter as tk
-    from idlelib.Percolator import Percolator
+    from idlelib.percolator import Percolator
     undowin = tk.Toplevel()
     undowin.title("Test UndoDelegator")
     width, height, x, y = list(map(int, re.split('[x+]', parent.geometry())))
diff --git a/Lib/idlelib/zoomheight.py b/Lib/idlelib/zoomheight.py
index a5d679e..0016e9d 100644
--- a/Lib/idlelib/zoomheight.py
+++ b/Lib/idlelib/zoomheight.py
@@ -3,7 +3,7 @@
 import re
 import sys
 
-from idlelib import macosxSupport
+from idlelib import macosx
 
 class ZoomHeight:
 
@@ -32,7 +32,7 @@
         newy = 0
         newheight = newheight - 72
 
-    elif macosxSupport.isAquaTk():
+    elif macosx.isAquaTk():
         # The '88' below is a magic number that avoids placing the bottom
         # of the window below the panel on my machine. I don't know how
         # to calculate the correct value for this with tkinter.