diff -r 8734e881c400 Lib/idlelib/Checker.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Lib/idlelib/Checker.py	Tue Jul 01 22:55:07 2014 +0530
@@ -0,0 +1,298 @@
+import os
+from subprocess import Popen, PIPE
+from tempfile import NamedTemporaryFile
+import tkinter as tk
+import tkinter.messagebox as tkMessageBox
+from idlelib.OutputWindow import OutputWindow
+from idlelib.configHandler import idleConf
+
+def get_checkers():
+    return idleConf.GetSectionList('user', 'checker')
+
+def get_enabled_checkers():
+    return [c for c in get_checkers() if idleConf.GetOption('checker', c,
+        'enabled', type='bool')]
+
+def get_checker_config(checker):
+    if checker == '':
+        raise ValueError('Checker name cannot be empty')
+    config = {}
+    config['enabled'] = idleConf.GetOption('checker', checker, 'enabled',
+            type='bool')
+    config['name'] = checker
+    config['command'] = idleConf.GetOption('checker', checker, 'command')
+    config['additional'] = idleConf.GetOption('checker', checker,
+            'additional')
+    return config
+
+
+class Checker:
+
+    menudefs = [
+            ('run', [None,
+                    ('Config Checkers', '<<config-checker>>')
+                    ]
+            )
+    ]
+
+    def __init__(self, editwin):
+        self.editwin = editwin
+        self.parent = self.editwin.top
+        self.update_menu()
+
+    def config_checker_event(self, event):
+        dialog = self.dialog = tk.Toplevel(self.parent)
+        dialog.transient(self.parent)
+        dialog.wm_title('Config Checkers')
+        dialog.geometry('+%d+%d' % (self.parent.winfo_rootx() + 30,
+                                    self.parent.winfo_rooty() + 30))
+        titleLabel = tk.Label(dialog, text='Configure Checkers')
+        self.listbox = tk.Listbox(dialog, selectmode=tk.SINGLE)
+        self.update_listbox()
+        addButton = tk.Button(dialog, text='Add checker',
+                             command=self.add_checker)
+        editButton = tk.Button(dialog, text='Edit Checker',
+                              command=self.edit_checker)
+        removeButton = tk.Button(dialog, text='Remove Checker',
+                                command=self.remove_checker)
+        titleLabel.pack()
+        self.listbox.pack()
+        addButton.pack(side=tk.LEFT)
+        editButton.pack(side=tk.LEFT)
+        removeButton.pack(side=tk.LEFT)
+
+    def update_listbox(self):
+        self.listbox.delete(0, tk.END)
+        checkers = get_checkers()
+        for c in checkers:
+            self.listbox.insert(tk.END, c)
+
+    def add_checker(self):
+        ConfigCheckerDialog(self.editwin, self)
+
+    def _selected_checker(self):
+        index = self.listbox.curselection()
+        if index:
+            checker = self.listbox.get(index)
+            return checker
+        else:
+            return None
+
+    def edit_checker(self):
+        checker = self._selected_checker()
+        if checker:
+            ConfigCheckerDialog(self.editwin, self, checker)
+        else:
+            tkMessageBox.showerror(title='No Checker Selected',
+                                message='Select an existing checker to edit',
+                                parent=self.dialog)
+
+    def remove_checker(self):
+        checker = self._selected_checker()
+        if checker:
+            idleConf.userCfg['checker'].remove_option(checker, 'enabled')
+            idleConf.userCfg['checker'].remove_option(checker, 'command')
+            idleConf.userCfg['checker'].remove_option(checker, 'additional')
+            idleConf.userCfg['checker'].Save()
+        else:
+            tkMessageBox.showerror(title='No Checker Selected',
+                                message='Selectan existing checker to remove',
+                                parent=self.dialog)
+        self.update_listbox()
+        self.update_menu()
+
+    def update_menu(self):
+        menu = self.editwin.menudict.get('run')
+        start = menu.index('Config Checkers') + 1
+        end = menu.index(tk.END)
+        if start < end:
+            menu.delete(start, end)
+        if start == end:
+            menu.delete(start)
+        for checker in get_enabled_checkers():
+            label = 'Run {}'.format(checker)
+            menu.add_command(label=label,
+                    command=lambda checker=checker:self.run_checker(checker))
+
+    def run_checker(self, checker=None):
+        """Run the 3rd party checker 'checker' and display result in a new
+        outputwindow"""
+        orig_file = self.editwin.io.filename
+        if not orig_file:
+            return
+        saved = self.editwin.get_saved()
+        if saved:
+            _file = orig_file
+        else:
+            _file = NamedTemporaryFile(suffix='.tmp',
+                                       delete=False).name
+            text = self.editwin.text.get('1.0', 'end')
+            with open(_file, 'w') as f:
+                f.write(text)
+        if checker:
+            additional_args = get_checker_config(checker)['additional']
+        else:
+            checker = self.name.get()
+            additional_args = self.additional.get()
+        args = [checker, _file, additional_args]
+        args = [os.path.expanduser(arg) for arg in args if arg]
+        try:
+            proc = Popen(args, stdout=PIPE, stderr=PIPE)
+            proc.wait()
+            output, error = map(lambda b:b.decode('utf-8'), proc.communicate())
+        except Exception as e:
+            output = ''
+            error = str(e)
+        if not saved:
+            os.unlink(_file)
+            output, error = self.process_text(_file, output, error)
+        self.show_result(output, error)
+
+    def show_result(self, output, error):
+        """Utility method to display 'output' and 'error' in a new
+        OutputWindow"""
+        theme = idleConf.CurrentTheme()
+        stdout = idleConf.GetHighlight(theme, 'stdout')
+        stderr = idleConf.GetHighlight(theme, 'stderr')
+        tagdefs = {'stdout':stdout, 'stderr':stderr}
+        outputwindow = OutputWindow(self.editwin.flist)
+        for tag, cnf in tagdefs.items():
+            outputwindow.text.tag_configure(tag, **cnf)
+        outputwindow.write(error, 'stderr')
+        outputwindow.write(output, 'stdout')
+
+    def process_text(self, temp_file, output, error):
+        orig_file = self.editwin.io.filename
+        orig_dirname = os.path.dirname(orig_file)
+        orig_basename = os.path.basename(orig_file)
+        orig_modulename = os.path.splitext(orig_basename)
+
+        temp_dirname = os.path.dirname(temp_file)
+        temp_basename = os.path.basename(temp_file)
+        temp_modulename = os.path.splitext(temp_basename)
+
+        output = output.replace(temp_modulename[0], orig_modulename[0])
+        output = output.replace(temp_modulename[1], orig_modulename[1])
+        output = output.replace(temp_basename, orig_basename)
+        output = output.replace(temp_dirname, orig_dirname)
+        output = output.replace(temp_file, orig_file)
+
+        error = error.replace(temp_modulename[0], orig_modulename[0])
+        error = error.replace(temp_modulename[1], orig_modulename[1])
+        error = error.replace(temp_basename, orig_basename)
+        error = error.replace(temp_dirname, orig_dirname)
+        error = error.replace(temp_file, temp_file)
+
+        return output, error
+
+class ConfigCheckerDialog(tk.Toplevel):
+
+    def __init__(self, editwin, _checker, checker=None):
+        tk.Toplevel.__init__(self, editwin.top)
+        self.editwin = editwin
+        self._checker = _checker
+        self.checker = checker
+        self.parent = parent = self.editwin.top
+        self.name = tk.StringVar(parent)
+        self.command = tk.StringVar(parent)
+        self.enabled = tk.StringVar(parent)
+        self.additional = tk.StringVar(parent)
+        if checker:
+            config = get_checker_config(checker)
+            self.name.set(config['name'])
+            self.command.set(config['command'])
+            self.additional.set(config['additional'])
+            self.enabled.set(config['enabled'])
+        self.create_widgets()
+
+    def create_widgets(self):
+        parent = self.parent
+        self.configure(borderwidth=5)
+        if self.checker:
+            title = 'Edit {} checker'.format(self.checker)
+        else:
+            title = 'Config new checker'
+        self.wm_title(title)
+        self.geometry('+%d+%d' % (parent.winfo_rootx() + 30,
+                                    parent.winfo_rooty() + 30))
+        self.transient(parent)
+        self.focus_set()
+        # frames creation
+        optionsFrame = tk.Frame(self)
+        buttonFrame = tk.Frame(self)
+
+        # optionsFrame
+        nameLabel = tk.Label(optionsFrame, text='Name of Checker')
+        commandLabel = tk.Label(optionsFrame, text='Command')
+        additionalLabel = tk.Label(optionsFrame, text='Additional Args')
+
+        self.nameEntry = tk.Entry(optionsFrame, textvariable=self.name)
+        self.commandEntry = tk.Entry(optionsFrame, textvariable=self.command)
+        self.additionalEntry = tk.Entry(optionsFrame,
+               textvariable=self.additional)
+        enabledCheckbutton = tk.Checkbutton(optionsFrame,
+                variable=self.enabled, text='Enable Checker?')
+
+        # buttonFrame
+        okButton = tk.Button(buttonFrame, text='Ok', command=self.ok)
+        cancelButton = tk.Button(buttonFrame, text='Cancel',
+                                 command=self.cancel)
+
+        # frames packing
+        optionsFrame.pack()
+        buttonFrame.pack()
+        # optionsFrame packing
+        nameLabel.pack()
+        self.nameEntry.pack()
+        commandLabel.pack()
+        self.commandEntry.pack()
+        additionalLabel.pack()
+        self.additionalEntry.pack()
+        enabledCheckbutton.pack()
+        # buttonFrame packing
+        okButton.pack()
+        cancelButton.pack()
+
+    def name_ok(self):
+        name = self.name.get()
+        ok = True
+        if name == '':
+            tkMessageBox.showerror(title='Name Error',
+                                message='No Name Specified', parent=self)
+            ok = False
+        return ok
+
+    def command_ok(self):
+        command = self.command.get()
+        ok = True
+        if command == '':
+            tkMessageBox.showerror(title='Command Error',
+                                message='No Command Specified', parent=self)
+            ok = False
+        return ok
+
+    def additional_ok(self):
+        ok = True
+        return ok
+
+    def ok(self):
+        _ok = self.name_ok() and self.command_ok() and self.additional_ok()
+        if _ok:
+            name = self.name.get()
+            idleConf.userCfg['checker'].SetOption(name, 'enabled',
+                    self.enabled.get())
+            idleConf.userCfg['checker'].SetOption(name, 'command',
+                    self.command.get())
+            idleConf.userCfg['checker'].SetOption(name, 'additional',
+                    self.additional.get())
+
+            idleConf.userCfg['checker'].Save()
+            self.close()
+
+    def cancel(self):
+        self.close()
+
+    def close(self):
+        self._checker.update_listbox()
+        self._checker.update_menu()
+        self.destroy()
diff -r 8734e881c400 Lib/idlelib/config-extensions.def
--- a/Lib/idlelib/config-extensions.def	Sun Jun 29 00:46:45 2014 +0200
+++ b/Lib/idlelib/config-extensions.def	Tue Jul 01 22:55:07 2014 +0530
@@ -94,3 +94,9 @@
 enable_shell=0
 enable_editor=1
 
+[Checker]
+enable=1
+enable_shell=0
+enable_editor=1
+[Checker_bindings]
+config-checker=
diff -r 8734e881c400 Lib/idlelib/configHandler.py
--- a/Lib/idlelib/configHandler.py	Sun Jun 29 00:46:45 2014 +0200
+++ b/Lib/idlelib/configHandler.py	Tue Jul 01 22:55:07 2014 +0530
@@ -162,6 +162,7 @@
         (user home dir)/.idlerc/config-extensions.cfg
         (user home dir)/.idlerc/config-highlight.cfg
         (user home dir)/.idlerc/config-keys.cfg
+        (user home dir)/.idlerc/config-checker.cfg
     """
     def __init__(self):
         self.defaultCfg={}
@@ -182,7 +183,7 @@
         else: # we were exec'ed (for testing only)
             idleDir=os.path.abspath(sys.path[0])
         userDir=self.GetUserCfgDir()
-        configTypes=('main','extensions','highlight','keys')
+        configTypes=('main','extensions','highlight','keys', 'checker')
         defCfgFiles={}
         usrCfgFiles={}
         for cfgType in configTypes: #build config file names
@@ -282,9 +283,11 @@
         Get a list of sections from either the user or default config for
         the given config type.
         configSet must be either 'user' or 'default'
-        configType must be one of ('main','extensions','highlight','keys')
+        configType must be one of ('main','extensions','highlight','keys',
+        'checker')
         """
-        if not (configType in ('main','extensions','highlight','keys')):
+        if not (configType in ('main','extensions','highlight','keys',
+        'checker')):
             raise InvalidConfigType('Invalid configType specified')
         if configSet == 'user':
             cfgParser=self.userCfg[configType]
diff -r 8734e881c400 Lib/idlelib/idle_test/mock_tk.py
--- a/Lib/idlelib/idle_test/mock_tk.py	Sun Jun 29 00:46:45 2014 +0200
+++ b/Lib/idlelib/idle_test/mock_tk.py	Tue Jul 01 22:55:07 2014 +0530
@@ -296,3 +296,12 @@
     def bind(sequence=None, func=None, add=None):
         "Bind to this widget at event sequence a call to function func."
         pass
+
+class Listbox:
+    """Mock for tk.Listbox"""
+    def __init__(self, *args, **kwargs):
+        self.listitems = []
+        self.selection = None
+
+    def curselection(self):
+        return self.selection
diff -r 8734e881c400 Lib/idlelib/idle_test/test_checker.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Lib/idlelib/idle_test/test_checker.py	Tue Jul 01 22:55:07 2014 +0530
@@ -0,0 +1,116 @@
+import unittest
+from idlelib.idle_test.mock_tk import Var, Mbox, Listbox
+import idlelib.Checker as checker
+
+checker_dialog = checker.Checker
+config_checker_dialog = checker.ConfigCheckerDialog
+
+class Dummy_checker:
+    # Mock for testing methods of Checker
+    edit_checker = checker_dialog.edit_checker
+    _selected_checker = checker_dialog._selected_checker
+    listbox = Listbox()
+
+class Dummy_config_checker_dialog:
+    # Mock for testing methods of ConfigCheckerDialog
+    name_ok = config_checker_dialog.name_ok
+    command_ok = config_checker_dialog.command_ok
+    additional_ok = config_checker_dialog.additional_ok
+    ok = config_checker_dialog.ok
+    cancel = config_checker_dialog.cancel
+
+    name = Var()
+    command = Var()
+    additional = Var()
+    destroyed = False
+    def destroy(cls):
+        cls.destroyed = True
+
+# methods call Mbox.showerror if values are not ok
+orig_mbox = checker.tkMessageBox
+showerror = Mbox.showerror
+
+class CheckerUtilityTest(unittest.TestCase):
+    def test_get_checkers(self):
+        self.assertIsInstance(checker.get_checkers(), list)
+
+    def test_get_enabled_checkers(self):
+        checkers_list = checker.get_checkers()
+        enabled_checkers = checker.get_enabled_checkers()
+        self.assertIsInstance(enabled_checkers, list)
+        self.assertTrue(set(enabled_checkers) <= set(checkers_list))
+
+    def test_checker_config(self):
+        get = checker.get_checker_config
+        with self.assertRaises(ValueError) as ve:
+            get('')
+        self.assertIn('empty', str(ve.exception))
+        enabled_checkers = checker.get_enabled_checkers()
+        if enabled_checkers:
+            c = enabled_checkers[0]
+            cfg_list = list(get(c))
+            self.assertIn('enabled', cfg_list)
+            self.assertIn('name', cfg_list)
+            self.assertIn('command', cfg_list)
+            self.assertIn('additional', cfg_list)
+
+
+class CheckerTest(unittest.TestCase):
+    dialog = Dummy_checker()
+
+    @classmethod
+    def setUpClass(cls):
+        cls.dialog.dialog = cls.dialog
+        checker.tkMessageBox = Mbox
+
+    @classmethod
+    def tearDownClass(cls):
+        checker.tkMessageBox = orig_mbox
+
+    def test_blank_edit(self):
+        self.assertIsNone(self.dialog.listbox.selection)
+        showerror.title = ''
+        showerror.message = ''
+        self.dialog.edit_checker()
+        self.assertEqual(showerror.title, 'No Checker Selected')
+        self.assertIn('existing', showerror.message)
+
+class ConfigCheckerDialogTest(unittest.TestCase):
+    dialog = Dummy_config_checker_dialog()
+
+    @classmethod
+    def setUpClass(cls):
+        checker.tkMessageBox = Mbox
+
+    @classmethod
+    def tearDownClass(cls):
+        checker.tkMessageBox = orig_mbox
+
+    def test_blank_name(self):
+        self.dialog.name.set('')
+        self.assertFalse(self.dialog.name_ok())
+        self.assertEqual(showerror.title, 'Name Error')
+        self.assertIn('No', showerror.message)
+
+    def test_good_name(self):
+        self.dialog.name.set('pyflakes')
+        self.assertTrue(self.dialog.name_ok())
+
+    def test_blank_command(self):
+        self.dialog.command.set('')
+        self.assertFalse(self.dialog.command_ok())
+        self.assertEqual(showerror.title, 'Command Error')
+        self.assertIn('No', showerror.message)
+
+    def test_good_command(self):
+        self.dialog.command.set('/bin/pyflakes')
+        self.assertTrue(self.dialog.command_ok())
+
+    def test_good_additional(self):
+        self.dialog.additional.set('')
+        self.assertTrue(self.dialog.additional_ok())
+        self.dialog.additional.set('--help')
+        self.assertTrue(self.dialog.additional_ok())
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2)