diff --git a/Lib/packaging/command/bdist_dumb.py b/Lib/packaging/command/bdist_dumb.py
index d5773f0..309f64f 100644
--- a/Lib/packaging/command/bdist_dumb.py
+++ b/Lib/packaging/command/bdist_dumb.py
@@ -5,9 +5,9 @@
 """
 
 import os
-
 from shutil import rmtree
 from sysconfig import get_python_version
+
 from packaging.util import get_platform
 from packaging.command.cmd import Command
 from packaging.errors import PackagingPlatformError
@@ -24,7 +24,7 @@
                      "platform name to embed in generated filenames "
                      "(default: %s)" % get_platform()),
                     ('format=', 'f',
-                     "archive format to create (tar, gztar, zip)"),
+                     "archive format to create (tar, gztar, bztar, zip)"),
                     ('keep-temp', 'k',
                      "keep the pseudo-installation tree around after " +
                      "creating the distribution archive"),
diff --git a/Lib/packaging/compat.py b/Lib/packaging/compat.py
index a82efd3..dcb58f5 100644
--- a/Lib/packaging/compat.py
+++ b/Lib/packaging/compat.py
@@ -1,8 +1,4 @@
-"""Compatibility helpers.
-
-This module provides classes, variables and imports which are used to
-support packaging across Python 2.x and 3.x.
-"""
+"""Compatibility helpers."""
 
 from packaging import logger
 
@@ -10,8 +6,6 @@
 # XXX Having two classes with the same name is not a good thing.
 # XXX 2to3-related code should move from util to this module
 
-# TODO Move common code here: PY3 (bool indicating if we're on 3.x), any, etc.
-
 try:
     from packaging.util import Mixin2to3 as _Mixin2to3
     _CONVERT = True
diff --git a/Lib/packaging/metadata.py b/Lib/packaging/metadata.py
index a3db51c..c13acbe 100644
--- a/Lib/packaging/metadata.py
+++ b/Lib/packaging/metadata.py
@@ -552,16 +552,17 @@
         return data
 
     # Mapping API
+    # XXX these methods should return views or sets in 3.x
 
     def keys(self):
-        return _version2fieldlist(self['Metadata-Version'])
+        return list(_version2fieldlist(self['Metadata-Version']))
 
     def __iter__(self):
         for key in self.keys():
             yield key
 
     def values(self):
-        return [self[key] for key in list(self.keys())]
+        return [self[key] for key in self.keys()]
 
     def items(self):
-        return [(key, self[key]) for key in list(self.keys())]
+        return [(key, self[key]) for key in self.keys()]
diff --git a/Lib/packaging/pypi/simple.py b/Lib/packaging/pypi/simple.py
index 76aad02..9faabaa 100644
--- a/Lib/packaging/pypi/simple.py
+++ b/Lib/packaging/pypi/simple.py
@@ -23,12 +23,11 @@
 from packaging import __version__ as packaging_version
 from packaging.pypi.base import BaseClient
 from packaging.pypi.dist import (ReleasesList, EXTENSIONS,
-                                  get_infos_from_url, MD5_HASH)
+                                 get_infos_from_url, MD5_HASH)
 from packaging.pypi.errors import (PackagingPyPIError, DownloadError,
-                                    UnableToDownload, CantParseArchiveName,
-                                    ReleaseNotFound, ProjectNotFound)
+                                   UnableToDownload, CantParseArchiveName,
+                                   ReleaseNotFound, ProjectNotFound)
 from packaging.pypi.mirrors import get_mirrors
-from packaging.metadata import Metadata
 
 __all__ = ['Crawler', 'DEFAULT_SIMPLE_INDEX_URL']
 
diff --git a/Lib/packaging/tests/test_command_bdist_dumb.py b/Lib/packaging/tests/test_command_bdist_dumb.py
index cc03fa5..8e2d497 100644
--- a/Lib/packaging/tests/test_command_bdist_dumb.py
+++ b/Lib/packaging/tests/test_command_bdist_dumb.py
@@ -35,7 +35,7 @@
 
         dist = Distribution({'name': 'foo', 'version': '0.1',
                              'py_modules': ['foo'],
-                             'home-page': 'xxx', 'author': 'xxx',
+                             'home_page': 'xxx', 'author': 'xxx',
                              'author_email': 'xxx'})
         os.chdir(pkg_dir)
         cmd = bdist_dumb(dist)
diff --git a/Lib/packaging/tests/test_command_build_ext.py b/Lib/packaging/tests/test_command_build_ext.py
index c84631c..2926c37 100644
--- a/Lib/packaging/tests/test_command_build_ext.py
+++ b/Lib/packaging/tests/test_command_build_ext.py
@@ -4,14 +4,13 @@
 import sysconfig
 import textwrap
 from io import StringIO
-from sysconfig import _CONFIG_VARS
 from packaging.dist import Distribution
 from packaging.errors import (UnknownFileError, CompileError,
                               PackagingPlatformError)
 from packaging.command.build_ext import build_ext
 from packaging.compiler.extension import Extension
-from test.script_helper import assert_python_ok
 
+from test.script_helper import assert_python_ok
 from packaging.tests import support, unittest, verbose
 
 
@@ -75,16 +74,16 @@
 
         sys.platform = 'sunos'  # fooling finalize_options
 
-        old_var = _CONFIG_VARS.get('Py_ENABLE_SHARED')
-        _CONFIG_VARS['Py_ENABLE_SHARED'] = 1
+        old_var = sysconfig.get_config_var('Py_ENABLE_SHARED')
+        sysconfig._CONFIG_VARS['Py_ENABLE_SHARED'] = 1
         try:
             cmd.ensure_finalized()
         finally:
             sys.platform = old
             if old_var is None:
-                del _CONFIG_VARS['Py_ENABLE_SHARED']
+                del sysconfig._CONFIG_VARS['Py_ENABLE_SHARED']
             else:
-                _CONFIG_VARS['Py_ENABLE_SHARED'] = old_var
+                sysconfig._CONFIG_VARS['Py_ENABLE_SHARED'] = old_var
 
         # make sure we get some library dirs under solaris
         self.assertGreater(len(cmd.library_dirs), 0)
diff --git a/Lib/packaging/tests/test_command_register.py b/Lib/packaging/tests/test_command_register.py
index 9c64e2d..9872e2e 100644
--- a/Lib/packaging/tests/test_command_register.py
+++ b/Lib/packaging/tests/test_command_register.py
@@ -99,7 +99,7 @@
 
     def _get_cmd(self, metadata=None):
         if metadata is None:
-            metadata = {'home-page': 'xxx', 'author': 'xxx',
+            metadata = {'home_page': 'xxx', 'author': 'xxx',
                         'author_email': 'xxx',
                         'name': 'xxx', 'version': 'xxx'}
         pkg_info, dist = self.create_dist(**metadata)
diff --git a/Lib/packaging/tests/test_dist.py b/Lib/packaging/tests/test_dist.py
index 8d91a92..f912c6f 100644
--- a/Lib/packaging/tests/test_dist.py
+++ b/Lib/packaging/tests/test_dist.py
@@ -72,7 +72,7 @@
         Distribution(attrs={'author': 'xxx',
                             'name': 'xxx',
                             'version': '1.2',
-                            'home-page': 'xxxx',
+                            'home_page': 'xxxx',
                             'badoptname': 'xxx'})
         logs = self.get_logs(logging.WARNING)
         self.assertEqual(len(logs), 1)
@@ -82,7 +82,7 @@
         # an empty options dictionary should not stay in the
         # list of attributes
         dist = Distribution(attrs={'author': 'xxx', 'name': 'xxx',
-                                   'version': '1.2', 'home-page': 'xxxx',
+                                   'version': '1.2', 'home_page': 'xxxx',
                                    'options': {}})
 
         self.assertEqual([], self.get_logs(logging.WARNING))
@@ -99,7 +99,7 @@
         dist = Distribution(attrs={'author': 'xxx',
                                    'name': 'xxx',
                                    'version': 'xxx',
-                                   'home-page': 'xxxx',
+                                   'home_page': 'xxxx',
                                    'options': {'sdist': {'owner': 'root'}}})
 
         self.assertIn('owner', dist.get_option_dict('sdist'))
diff --git a/Lib/packaging/tests/test_metadata.py b/Lib/packaging/tests/test_metadata.py
index 68b3d97..6b7dd38 100644
--- a/Lib/packaging/tests/test_metadata.py
+++ b/Lib/packaging/tests/test_metadata.py
@@ -101,7 +101,7 @@
 
         # XXX caveat: the keys method and friends are not 3.x-style views
         # should be changed or documented
-        self.assertEqual(list(metadata), list(metadata.keys()))
+        self.assertEqual(list(metadata), metadata.keys())
 
     def test_read_metadata(self):
         fields = {'name': 'project',
@@ -301,7 +301,7 @@
         Metadata(mapping={'author': 'xxx',
                           'name': 'xxx',
                           'version': 'xxx',
-                          'home-page': 'xxxx'})
+                          'home_page': 'xxxx'})
         logs = self.get_logs(logging.WARNING)
         self.assertEqual(1, len(logs))
         self.assertIn('not a valid version', logs[0])