diff --git a/bootstrap.py b/bootstrap.py
index a629566..a459921 100644
--- a/bootstrap.py
+++ b/bootstrap.py
@@ -25,7 +25,10 @@
 
 from optparse import OptionParser
 
-tmpeggs = tempfile.mkdtemp()
+__version__ = '2015-07-01'
+# See zc.buildout's changelog if this version is up to date.
+
+tmpeggs = tempfile.mkdtemp(prefix='bootstrap-')
 
 usage = '''\
 [DESIRED PYTHON FOR BUILDOUT] bootstrap.py [options]
@@ -40,8 +43,9 @@
 '''
 
 parser = OptionParser(usage=usage)
-parser.add_option("-v", "--version", help="use a specific zc.buildout version")
-
+parser.add_option("--version",
+                  action="store_true", default=False,
+                  help=("Return bootstrap.py version."))
 parser.add_option("-t", "--accept-buildout-test-releases",
                   dest='accept_buildout_test_releases',
                   action="store_true", default=False,
@@ -59,25 +63,33 @@
 parser.add_option("--allow-site-packages",
                   action="store_true", default=False,
                   help=("Let bootstrap.py use existing site packages"))
+parser.add_option("--buildout-version",
+                  help="Use a specific zc.buildout version")
 parser.add_option("--setuptools-version",
-                  help="use a specific setuptools version")
-
+                  help="Use a specific setuptools version")
+parser.add_option("--setuptools-to-dir",
+                  help=("Allow for re-use of existing directory of "
+                        "setuptools versions"))
 
 options, args = parser.parse_args()
+if options.version:
+    print("bootstrap.py version %s" % __version__)
+    sys.exit(0)
+
 
 ######################################################################
 # load/install setuptools
 
 try:
-    if options.allow_site_packages:
-        import setuptools
-        import pkg_resources
     from urllib.request import urlopen
 except ImportError:
     from urllib2 import urlopen
 
 ez = {}
-exec(urlopen('https://bootstrap.pypa.io/ez_setup.py').read(), ez)
+if os.path.exists('ez_setup.py'):
+    exec(open('ez_setup.py').read(), ez)
+else:
+    exec(urlopen('https://bootstrap.pypa.io/ez_setup.py').read(), ez)
 
 if not options.allow_site_packages:
     # ez_setup imports site, which adds site packages
@@ -88,12 +100,19 @@
     # We can't remove these reliably
     if hasattr(site, 'getsitepackages'):
         for sitepackage_path in site.getsitepackages():
-            sys.path[:] = [x for x in sys.path if sitepackage_path not in x]
+            # Strip all site-packages directories from sys.path that
+            # are not sys.prefix; this is because on Windows
+            # sys.prefix is a site-package directory.
+            if sitepackage_path != sys.prefix:
+                sys.path[:] = [x for x in sys.path
+                               if sitepackage_path not in x]
 
 setup_args = dict(to_dir=tmpeggs, download_delay=0)
 
 if options.setuptools_version is not None:
     setup_args['version'] = options.setuptools_version
+if options.setuptools_to_dir is not None:
+    setup_args['to_dir'] = options.setuptools_to_dir
 
 ez['use_setuptools'](**setup_args)
 import setuptools
@@ -110,7 +129,12 @@
 
 ws = pkg_resources.working_set
 
+setuptools_path = ws.find(
+    pkg_resources.Requirement.parse('setuptools')).location
+
+# Fix sys.path here as easy_install.pth added before PYTHONPATH
 cmd = [sys.executable, '-c',
+       'import sys; sys.path[0:0] = [%r]; ' % setuptools_path +
        'from setuptools.command.easy_install import main; main()',
        '-mZqNxd', tmpeggs]
 
@@ -123,11 +147,8 @@
 if find_links:
     cmd.extend(['-f', find_links])
 
-setuptools_path = ws.find(
-    pkg_resources.Requirement.parse('setuptools')).location
-
 requirement = 'zc.buildout'
-version = options.version
+version = options.buildout_version
 if version is None and not options.accept_buildout_test_releases:
     # Figure out the most recent final version of zc.buildout.
     import setuptools.package_index
@@ -167,7 +188,7 @@ def _final_version(parsed_version):
 cmd.append(requirement)
 
 import subprocess
-if subprocess.call(cmd, env=dict(os.environ, PYTHONPATH=setuptools_path)) != 0:
+if subprocess.call(cmd) != 0:
     raise Exception(
         "Failed to execute command:\n%s" % repr(cmd)[1:-1])